12. Nobody has ever seen a new species evolve.
Speciation is probably fairly rare and in many cases might take centuries. Furthermore, recognizing a new species during a formative stage can be difficult, because biologists sometimes disagree about how best to define a species. The most widely used definition, Mayr’s Biological Species Concept, recognizes a species as a distinct community of reproductively isolated populations–sets of organisms that normally do not or cannot breed outside their community. In practice, this standard can be difficult to apply to organisms isolated by distance or terrain or to plants (and, of course, fossils do not breed). Biologists therefore usually use organisms’ physical and behavioral traits as clues to their species membership.
Nevertheless, the scientific literature does contain reports of apparent speciation events in plants, insects and worms. In most of these experiments, researchers subjected organisms to various types of selection–for anatomical differences, mating behaviors, habitat preferences and other traits–and found that they had created populations of organisms that did not breed with outsiders. For example, William R. Rice of the University of New Mexico and George W. Salt of the University of California at Davis demonstrated that if they sorted a group of fruit flies by their preference for certain environments and bred those flies separately over 35 generations, the resulting flies would refuse to breed with those from a very different environment. 15 Answers to Creationist Nonsense
Tag Archives: evolution
We saw 12 Years a Slave last night. Powerful.
I was interested to learn that a currently fashionable notion of Christian fundamentalists holds that Adam, being a farmer, had to be from the vicinity of modern day Turkey. Adam was the first man by virtue of having genes which allowed him to be an agriculturist right from the git-go. So, the other older ‘out of Africa’ humans were actually not humans like Adam was a human because their more primitive genes only allowed them to be hunter/gatherers. Oh, and Adam being the first human and created by God, lived to be 930 years old too.
While some understand the reference to Adam in Genesis to be a general reference to mankind as a whole or the creation of more than one couple, most conservative scholars reject such a view and understand the Genesis account to refer to the creation of a literal Adam and Eve as a single couple. This is further supported by the NT. For instance Paul understood the OT to refer to a literal Adam and Eve (see Rom. 5:14; 2 Cor. 11:3; 1 Tim. 2:12-13). He clearly understood the reference to Adam and Eve to the first man and woman.
As to incest, it was not considered a sin and was not prohibited for Adam and early man. If the race was to populate and fulfill the command of Gen. 1:28, there is little doubt that Adam’s sons and daughters had to have married their own sisters and brothers if the race was to populate the earth, but due to the purity of the race as evidenced also by the long length of life, there were no adverse effects as we see happening today. Gradually, as the effects of sin took its toll on the human race, marrying one’s own sister, etc., began to create hereditary problems.
Here is Ryrie’s comment on this issue from his book Basic Theology (1986 ed) which I would highly recommend.
Though by many inerrantists the question of where Cain got his wife would not be considered a problem at all, this question is often used by those who try to demonstrate that the Bible is unreliable in what it claims. How could it claim that Adam and Eve were the first human beings who had two sons, one of whom murdered the other, and yet who produced a large race of people? Clearly, the Bible does teach that Adam and Eve were the first created human beings. The Lord affirmed this in Matthew 19:3-9. The genealogy of Christ is traced back to Adam (Luke 3:38). Jude 14 identifies Enoch as the seventh from Adam. This could hardly mean the seventh from “mankind,” an interpretation that would be necessary if Adam were not an individual as some claim. Clearly, Cain murdered Abel and yet many people were born. Where did Cain get his wife?
We know that Adam and Eve had other sons and daughters in addition to Abel, Cain, and Seth (Gen. 5:4), and if there was only one original family, then the first marriages had to be between brothers and sisters. Such marriages in the beginning were not harmful. Incest is dangerous because inherited mutant genes that produce deformed, sickly, or moronic children are more likely to find expression in children if those genes are carried by both parents. Certainly, Adam and Eve, coming from the creative hand of God, had no such mutant genes. Therefore, marriages between brothers and sisters, or nieces and nephews in the first and second generations following Adam and Eve would not have been dangerous.
Many, many generations later, by the time of Moses, incest was then prohibited in the Mosaic laws undoubtedly for two reasons: first, such mutations that caused deformity had accumulated to the point where such unions were genetically dangerous, and second, it was forbidden because of the licentious practices of the Egyptians and Canaanites and as a general protection against such in society. It should also be noted that in addition to the Bible most other legal codes refuse to sanction marriages of close relatives.
But here is another issue to consider. If one accepts the evolutionary hypothesis as to the origin of the human race, has that really relieved the issue of incest? Not unless you also propound the idea of the evolution of many pairs of beings, pre-human or whatever, at the same time. No matter what theory of the origin of the human race one may take, are we not driven to the conclusion that in the early history of the race, there was the need for intermarriage of the children of the same pair?
excerpted from The Search for Adam and Eve|John Tierney|Newsweek (1992)
To find Eve, Cann first had to persuade 147 pregnant women to donate their babies’ placentas to science. The placentas were the easiest way to get large samples of body tissue. Working with Wilson and a Berkeley biologist, Mark Stoneking, Cann selected women in America with ancestors from Africa, Europe, the Middle East and Asia. Her collaborators in New Guinea and Australia found Aboriginal women there. The babies were born, the placentas were gathered and frozen, and the tissue analysis began at Wilson’s lab in Berkeley. The tissues were ground in a souped-up Waring blender, spun in a centrifuge, mixed with a cell-breaking detergent, dyed flourescent and spun in a centrifuge again. The result was a clear liquid containing pure DNA.
This was not the DNA in the nucleus of the babies’ cells — the genes that determine most physical traits. This DNA came from outside the nucleus, in a compartment of the cell called the mitochondrion, which produces nearly all the energy to keep the cell alive. Scientists didn’t learn that the mitochondrion contained any genes until the 1960s. Then in the late 1970s they discovered that mitochondrial DNA was useful for tracing family trees because it’s inherited only from the mother. It’s not a mixture of both parents’ genes, like nuclear DNA, so it preserves a family record that isn’t scrambled every generation. It’s altered only by mutations — random, isolated mistakes in copying the genetic code, which are then passed on to the next generation. Each random mutation produces a new type of DNA as distinctive as a fingerprint. (The odds against two identical mitochondrial DNA’s appearing by chance are astronomical because there are so many ways to rearrange the units of the genetic code.)
To study these mutations, the Berkeley researchers cut each sample of DNA into segments that could be compared with the DNA of other babies. The differences were clear but surprisingly small. There weren’t even telltale distinctions between races. “We’re a young species, and there are really very few genetic differences among cultures,” Stoneking says. “In terms of our mitochondrial DNA, we’re much more closely related than almost any other vertebrate or mammalian species. You find New Guineans whose DNA is closer to other Asians’ than to other New Guineans’.” This may seem odd, given obvious racial differences. In fact, though, many differences represent trivial changes. Skin color, for instance, is a minor adaptation to climate — black in Africa for protection from the sun, white in Europe to absorb ultraviolet radiation that helps produce vitamin D. It takes only a few thousand years of evolution for skin color to change. The important changes — in brain size, for instance — can take hundreds of thousands of years.
The babies’ DNA seemed to form a family tree rooted in Africa. The DNA fell into two general categories, one found only in some babies of recent African descent, and a second found in everyone else and the other Africans. There was more diversity among the exclusively African group’s DNA, suggesting that it had accumulated more mutations because it had been around longer — and thus was the longest branch of the family tree. Apparently the DNA tree began in Africa, and then at some point a group of Africans emigrated, splitting off to form a second branch of DNA and carrying it to the rest of the world.
All the babies’ DNA could be traced back, ultimately, to one woman. In itself that wasn’t surprising, at least not to statisticians familiar with the quirks of genetic inheritance. “There must be one lucky mother,” Wilson says. “I worry about the term ‘Eve’ a little bit because of the implication that in her generation there were only two people. We are not saying that. We’re saying that in her generation there was some unknown number of men and women, probably a fairly large number, maybe a few thousand.” Many of these other women presumably are also our ancestors, because their nuclear genes would have been passed along to sons and daughters and eventually would have reached us. But at some point these other women’s mitochondrial genes disappeared because their descendants failed to have daughters, and so the mitochondrial DNA wasn’t passed along. At first glance it may seem inconceivable that the source of all mitochondrial DNA was a single woman, but it’s a well-established outcome of the laws of probability.
You can get a feel for the mathematics by considering a similar phenomenon: the disappearance of family names. Like mitochondrial DNA, these are generally passed along by only one sex — in this case, male. If a son marries and has two children, there’s a one-in-four chance that he’ll have two daughters. There’s also a chance that he won’t have any children. Eventually the odds catch up and a generation passes without a male heir, and the name disappears. “It’s an inevitable consequence of reproduction,” says John Avise, a geneticist at the University of Georgia. “Lineages will be going extinct all the time.” After 20 generations, for instance, it’s statistically likely that only 90 out of 100 original surnames will disappear. Avise cites the history of Pitcairn Island in the Pacific, which was settled in 1790 by 13 Tahitian women and six British sailors who had mutinied on the Bounty. After just seven generations, half of the original names have disappeared. If the island remained isolated, eventually everyone would have the same last name. At that point a visitor could conclude that every inhabitant descended from one man — call him the Pitcairn Adam.
So thus there must be a mitochondrial Eve, and even traditional anthopologists can’t really argue against her existence. What shocked them about Mitochondrial Mom was her birthday, which the Berkeley researchers calculated by counting the mutations that have occurred to her DNA. They looked at the most distant branches of the family tree — the DNA types most different from one another — and worked backward to figure out how many steps it would have taken for Eve’s original DNA to mutate into these different types. They assumed that these mutations occurred at a regular rate — a controversial assumption that might be wrong, but which has been supported by some studies of humans and animals. Over the course of a million years, it appears that 2 to 4 percent of the mitochondrial DNA components will mutate. By this molecular calculus, Eve must have lived about 200,000 years ago (the range is between 140,000 and 290,000 years). This date, published this past January by the Berkeley group, agrees with the estimate of a team of geneticists led by Douglas Wallace of Emory University.
One of the creationist lobbying organizations in Texas is named Texans for Better Science Education!
Here Texas goes again.
Creationists May Be Helping To Choose Biology Textbooks In Texas
Rebecca Klein, Huffington Post
It seems as though creationists could have a sizable influence in the decision over what biology textbooks students in Texas will use in the coming years.
The Texas Freedom Network, a nonprofit civil liberties group, posted on its website last week that it had discovered that six people chosen to review biology textbooks for the state had ties to creationism. Of the 28 invited to review textbooks, around a dozen went to Austin recently to make final textbook recommendations, the Texas Freedom Network wrote.
The Texas Freedom Network charged in a subsequent blog post that of that group of about 12, which approves the biology books used for at least the next eight years, four people had creationist backgrounds — a sizable proportion of the review team.
According to the Texas Freedom Network, some of the textbook panelists with a history of creationist beliefs include Raymond Bohlin, who is a research fellow at an institute that promotes intelligent design, and Walter Bradley, a retired professor who co-wrote a book about creationism. Bohlin and Bradley did not respond to multiple requests for comment.
Texas A&M chemistry professor Daniel Romo –- who is listed as a “Darwin Skeptic” on the Creation Science Hall of Fame website — confirmed to The Huffington Post via email that he is a member of the panel, although he did not attend the final review in Austin. Romo, who said he served on a previous panel regarding science textbooks, noted that he got involved with the textbook review after being “initially invited to submit an application by someone who partnered with Liberty Legal Institute.” The Liberty Legal Institute is a right-wing, nonprofit organization with the mission of “[restoring] religious liberty across America — in our schools, for our churches and throughout the public arena,” according to its website.
Where I live, Ohio, the state science standards thankfully, don’t allow the “controversy” to be taught in biology classes, but, the “controversy” and creationism worm their way into science classes in some school systems.
6 percent of scientists identify as Republicans. (“It Feels Like A Personal Assault:” How the GOP Drives Away Scientists – Salon)
When I meet a Republican in the flesh, it’s always amusing to find out if he or she finds modern biology to be rooted in Darwin, or not. It’s another one of my handful of acid tests.
I’m confident that a substantial number of Louisiana Republicans believe in creationism AND assert that the slow response to Katrina was Mr. Obama’s fault.
Hurricane Katrina: It’s Obama’s Fault, by George
Rosemary and Walter Brasch 8/31/2013
Almost one-third of Louisiana Republicans blame President Obama for the slow and largely ineffective response to Hurricane Katrina, which hit the Gulf Coast, Aug. 31, 2005. More than 1,800 were killed in Alabama, Mississippi, and Louisiana; estimates of property damage exceeded $100 billion.
Public Policy Polling reveals that 29 percent of the state’s Republicans blame Obama. Only 28 percent blame George W. Bush. The rest, according to the poll, don’t know who to blame.
The disaster occurred in the first year of George W. Bush’s second term. Barack Obama did not become president until more than three years later.
How Old Is the Human Race? va News.Discovery
A fifty percent increase in the age of our race is gigantic swing in a primary historical quantification.
The Genographic Project is a multiyear research initiative led by National Geographic Explorer-in-Residence Dr. Spencer Wells. Dr. Wells and a team of renowned international scientists are using cutting-edge genetic and computational technologies to analyze historical patterns in DNA from participants around the world to better understand our human genetic roots. The three components of the project are:
To gather and analyze research data in collaboration with indigenous and traditional peoples around the world
To invite the general public to join this real-time scientific project and to learn about their own deep ancestry by purchasing a Genographic Project Participation and DNA Ancestry Kit, Geno 2.0
To use a portion of the proceeds from Geno 2.0 kit sales to further research and the Genographic Legacy Fund, which in turn supports community-led indigenous conservation and revitalization projects
The Genographic Project is anonymous, nonmedical, and nonprofit, and all results are placed in the public domain following scientific peer publication.
Last-Minute Changes. Scientific orthodoxy says that human evolution stopped a long time ago. Did it? (Wall Street Journal, February 12, 2009) Christopher Chabris ‘psychology professor at Union College in Schenectady, N.Y.’
Where it is written:
But scientists do disagree over the pace and time-span of human evolution. Gregory Cochran and Henry Harpending begin “The 10,000 Year Explosion” with a remark from the paleontologist Stephen J. Gould, who said that “there’s been no biological change in humans for 40,000 or 50,000 years.” They also cite the evolutionist Ernst Mayr, who agrees that “man’s evolution towards manness suddenly came to a halt” in the same epoch.
Gould and Mayr do not constitute an orthodoxy. There is no orthodoxy that makes the claim Chabris has attached to it.
Evolution doesn’t stop, and it doesn’t stop for the cockroach and the hagfish and those bacteria that are apparently little changed over half-to-a-billion years. So the tag to the headline is a classic strawman. Chabris, you done over heated your pan o’ pablum. The controversy about the pace of human evolution is not very interesting to me personally, but there is no question about, nor orthodoxy suggesting, that the process of evolution can halt itself. It is, as it were, a dumb, albeit dynamic, kind of natural machine. Snails pace or cheetah; likely to vary for a lot of reasons between really really slow and faster. I suppose evolutionary homeostasis sort of happens given specific homeostatic environs, but I don’t know any biologist who claims mutations then halt.
Meanwhile, as long as anthropologists are coming under attack, they’ve earned the dull point of Richard Dawkins’s toy spear. Dawkins on Darwin. Why we really do need to know the amazing truth about evolution, and the equally amazing intellectual dishonesty of its enemies
Here is yet another article I would peg in the vain of post-sokalism. (I hope you get the ref.) Dawkins is (always) exercised at those who would seemingly relevatize scientific truth. He will eventually go off in the article on proponents of pseudo-science, but anthropology earns his ire in this dim section:
A scientist arrogantly asserts that thunder is not the triumphal sound of God’s balls banging together, nor is it Thor’s hammer. It is, instead, the reverberating echoes from the electrical discharges that we see as lightning. Poetic (or at least stirring) as those tribal myths may be, they are not actually true.
But now a certain kind of anthropologist can be relied on to jump up and say something like the following: Who are you to elevate scientific “truth” so? The tribal beliefs are true in the sense that they hang together in a meshwork of consistency with the rest of the tribe’s world view. Scientific “truth” is only one kind (“Western” truth, the anthropologist may call it, or even “patriarchal”). Like tribal truths, yours merely hang together with the world view that you happen to hold, which you call scientific. An extreme version of this viewpoint (I have actually encountered this) goes so far as to say that logic and evidence themselves are nothing more than instruments of masculine oppression over the “intuitive mind
Actually, Richard, scientific truth IS only one kind of truth. However the valency attached to any truth has to do with how it’s kind has been worked out. This inquiry into what are the applications of, and explanatory frameworks for, and what are consistent evaluative regimes, and, pertinent supportive logics and schemes of quantification, theorization, (etc.,) are crucial for the work of biologist and anthropologist and tribe. (Of course the tribesman’s points of emphasis and methodology may be quite different.) The kind posed by scientific truth is required to be scientifically worked out, but other kinds of truth are not required to be scientifically worked out. This isn’t to say science isn’t enabled so as to contest some other kind of truth–it may well be–but those other kinds of truths may also be of a different kind too. And, sorry Richard, but science literally came along in the history and development of, what I will term, sentient empiricism. So it strikes me as banal to suggest that scientific truth is per force superior if you don’t also proscribe the scientific domain and give it a historical qualification too.
I don’t see how relativism poses much of a threat to science. Two things I do know: scientists all the time do good work without being adept at the philosophy of science, and, some kinds of scientific truths are required to be provisional, and in a strong sense are thus relative to future developments.
Anthropologist Maurice Block wrote,
“If culture is the whole or a part what people must know in a particular social environment to operate efficently…” (in Language, Anthropology and Cognitive Science; 1991)
Full stop. Such peoples must know a bunch of unscientific and no less effective truth. Almost everybody is superstitious, hardly anybody is scientific, yet the anthropologist or some other kind of social scientist, may aim at giving an account for the basis of human efficiency given in a particular social environment, and include all sorts of other kinds of truths. These will be the truths the tribe deploys. In doing this, given are the many domains of inquiry that are commensurate with different kinds of tasks of understanding the nature of the tribal truths.
I decry the imposition of pseudo-science, such as creationism, into the science curriculum, but I am also fascinated by what accounts for the social impetus granted in the wish of people to have creationism taught in biology classes. Biology has nothing to say about this social phenomena. Except for polemicists who savage the implicit oddness of humans who are moved to promote pseudo-science.
There is so much long-standing controversy in anthropology and meta-anthropology over the valence of materialism and causal regimes and other knotty problems of reflexivity and stance and culturated bias and, in a word, subjectivities, that I would say to Dawkins, ‘anthropology has its own conundrums.’
(Dawkins) Like tribal truths, yours merely hang together with the world view that you happen to hold, which you call scientific.
This nominalist threat poses no contest to science at all. Yeah, it may be aggravating in the battle for column inches! Scientific truth is true in its well worked out ‘kind,’ or,–better–domain. Also, any anthropologist who maintains that scientists happen to hold a world view needs to explain what he or she means by ‘happen!’. But, who claims this?