144

Normal viruses infect cells in order to take advantage of cellular mechanisms to reproduce themselves. A class of viruses known as "retroviruses" have a slightly peculiar mechanism to achieve this - they synthesise a special enzyme called "reverse transcriptase", which translates their own RNA into DNA which is incorporated into the host cell's genome. The ...


80

Finally, a question covering my nominal area of expertise. To answer this question meaningfully we'll need to define some concepts but first. Yes, sort of. The statement is factually correct for reasonable interpretations. So, on to the terms. I'll link to a more specific stackexchange to support the definitions Homology. To draw an analogy: If someone said &...


29

Yes, genetically modified organisms (GMOs) are safe to consume. The American Association for the Advancement of Science, American Medical Association, World Health Organization, Food and Drug Administration, EU researchers all agree that GMOs are safe to eat. From the American Medical Association: Bioengineered foods have been consumed for close to 20 ...


23

This article has already been well-covered on the Internet. dinosaurs.about.com says "a complete hoax, albeit a very entertaining one." Snopes says "False" and explains the image is a kangaroo. Hoax-Slayer says "Hoax" and attributes the origin to "NewsHound, a website that publishes all manner of fanciful nonsense disguised as news reports." That's Nonsense ...


21

The claim that we share 50% of our DNA is likely a misquote of an older claim, that we share 50% of our genes with bananas. Both claims, as best I can tell, are false. I'll address each claim in turn. 50% of our DNA? The idea that we share 50% of our DNA is, by most obvious definitions of what that might mean, completely false, and trivially so. Per ...


19

This answer has three sections: Is human intelligence declining? No. Is the genetic foundation of human intelligence eroding? This has not been shown. Are other factors influencing the genetic component of intelligence? Probably. Is intelligence declining? No, human intelligence is not declining. In fact, it is increasing. This is actually stated in the ...


11

The hypothesis that humans descended from chimp-pig hybrids can be denied on the following points. Hybrids between different orders of mammals are very rare due to the genetic differences and differences in chromosome number. Despite McCarthy's suggestions to the contrary, reports of hybrids between different orders of mammal, though, are, literally, ...


11

No, this grossly summarised version of the paper overstates its conclusions. The quoted media reports suggest that the mother's genes account for all of the (variation) in intelligence of male children. They echo the statement you quoted from the final paragraph of the paper, but this final paragraph summary is an overstatement of the argument put forward ...


10

According to the US National Institutes of Health (NIH) (emphasis added): Researchers used to think that eye color was determined by a single gene and followed a simple inheritance pattern in which brown eyes were dominant to blue eyes. Under this model, it was believed that parents who both had blue eyes could not have a child with brown eyes. However, ...


10

Yes, this is accurate. The Wikipedia article has a good summary of the science, and you can also read this leaflet from the NHS in the UK. Your question about why this matters so much is a good one, and the answer is really interesting. It turns out that being "AS" (meaning one good gene and one faulty one) makes it very difficult for you to get malaria. So ...


9

This is not my area of scientific expertise. I cannot say if this study by Wilder et al is correct or not, but I can read the study and compare their conclusions to Baumeister's. Wilder et al conclude that women outnumber men in human ancestry, but they do not conclude that the ratio is two to one. They make a different conclusion about a two to one ratio, ...


8

I wish to add to the above answer. Approximately 9% of the genome is viral in origin, but current research suggests there is less of 'you' than there are other viral related sequences. Here is a very nice listing of the percentages of various genetic elements within the human genome: http://sandwalk.blogspot.com/2008/02/theme-genomes-junk-dna.html Although ...


8

While it is certainly not obvious to the eye, the fact that the closest relatives of crocodiles are birds appears to be well-established. These two clades are the only living members of a group known as archosaurs (Green et al. 2014): Crocodilians, birds, dinosaurs, and pterosaurs are a monophyletic group known as the archosaurs. Crocodilians and birds ...


6

I'll avoid trying to define what "additional genetic information" means and focus on what the Lenski experiment actually shows. The claim from Ken Ham that an existing gene was switched on is essentially correct, although there is a bit more to the whole thing. The genetic background for the evolution of the Cit+ trait is examined in Detail in the paper "...


6

The BBC produced a programme called "No More Boys and Girls", where they tried to do the opposite of most studies which attempt to measure the amount of gendered behaviour in infants or monkeys. The programme included the opinions of experts in the field, who suggested that while male and female brains are different from birth the differences are relatively ...


6

There is evidence of the opposite. Here are some comprehensive references that based on genetic evidence show how actual human evolution probably happened. Some basics: Pääbo, 2003. Stringer, 2012 comments on what makes modern humans human - of course without mentioning members of the Suidae family. Finally, the introduction of Harris and Nielsen, 2016 ...


5

Gene duplication is a very important way of creating new genes and hence it helps organisms to evolve. Once a gene is duplicated, the "spare" copy of the gene is effectively not needed by the cell, as the original still does the required job. This leaves the copy free to mutate in whatever way it wants. If it is a deleterious mutation, then the copy will ...


5

There's a significant body of evidence for this claim. Eg: an analysis of a first draft of the Neanderthal genome by the same team released in May 2010 indicates interbreeding may have occurred.1,2 Those of us who live outside Africa carry a little Neanderthal DNA in us," said Pääbo, who led the study. "The proportion of Neanderthal-inherited ...


5

In general terms, inbreeding is dangerous because it increases the chances of homozygosity. This means that for a particular gene, identical alleles of the gene are present on both homologous chromosomes. Those individuals result of the inbreeding have more chances of having recessive or deleterious traits. These are generally 'invisible', they don't ...


5

It looks like for young people (20's) both height and adiposity hover around .80. But as people get older genetic factors become less important for adiposity but remain somewhat stable (around .80) for height. A Twin Study of Human Obesity http://jama.jamanetwork.com/article.aspx?articleid=359582 Height, weight, and body mass index (BMI) were assessed in ...


5

The correlation is observable. Despite the ongoing replication crisis, this statistical effect is reported relatively often. But the correlation is small, the effect size is small and the explanatory background as well as its value is very limited. What causes it, if it is not spurious, remains elusive. Confounding factors, alternative explanations are under ...


4

Different populations may have different odors since earwax type and armpit odor may be correlated in certain select populations. Populations with dry earwax, such from East Asia, tend to sweat less and have little or no body odor, whereas the wet earwax populations of Africa and Europe sweat more and so may have greater body odor. "There are two kinds of ...


4

Ironically, the answer itself lies in anti-semitism. "Semite" itself does indeed come from "Shem"; according to the Encyclopedia of Christian Civilization, "August Ludwig von Schlözer is generally credited with the origin of the name Semite in 1781. Von Schlözer derived the term from Shem, the eldest son of Noah (Gen. 5:32; 6:10; 9:18; 10:1; 1 Chron. 1:4), ...


4

I find this question quite frustrating. It is a complete train-wreck, despite the OP's claims that it is "one of the better ones I've seen". It has received way too many upvotes from the community, despite comments pointing out some of its flaws. The answers have pussy-footed around this. It is time to go for the jugular. The claim makes no sense whatsoever....


3

Per Shai Carmi et.al. in 2014, "Ashkenazi Jews have an even admixture of European and Middle Eastern origins." Modelling of ancient histories for AJ and European populations using their joint allele frequency spectrum determines AJ to be an even admixture of European and likely Middle Eastern origins. We date the split between the two ancestral ...


3

Related question with some general info about inbreeding: Does inbreeding cause severe birth defects? Inbreeding is dangerous because it increases the chances of homozygosity, which means that for a particular gene, identical alleles of the gene are present on both homologous chromosomes. Those individuals result of the inbreeding have more chances ...


3

No, most recent studies give an equal or slightly older date for the Y Chromosome. An African American Paternal Lineage Adds an Extremely Ancient Root to the Human Y Chromosome Phylogenetic Tree (full text pdf) We report the discovery of an African American Y chromosome that carries the ancestral state of all SNPs that defined the basal portion of the ...


2

This question has remained unanswered yet not closed, so I'll give it a go. First of all, a clarification regarding the title. If phobias are genetic, by definition they can't be created in a generation and inherited. The term epigenetic is the one that might have led to this confusion, so I'll start by defining it. 1. Epigenetics Epigenetics is the ...


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