Heres the question: can a gene, be it one that causes a character trait or defect, die out? Or does it just become too recesive to be traced? With such a long history of humanity, I would think that some genes would have to die out and not be passed on to offspring. Please give a somewhat scientific answer, not just a "yes" or "no". Thanks in advance!
2007-01-29 14:36:28 · 6 answers · asked by Theredhairball 1 in Science & Mathematics ➔ Biology
Yes, genes that are not beneficial to the organism can eventually disappear from the gene pool. Genes are passed on to an organism from its father and its mother. The non-beneficial genes are either left behind as natural selection occurs, or passed on. Eventually, even the organism that inherited the genes will prove to be at a disadvantage compared to other organisms, and it will die before it has a chance to reproduce and pass this "bad" trait on.
Genes cannot be "too recessive". They're either there or not there; that is, if a trait is represented by a recessive allele, it may show up in the next generation, but if the next generation shows no signs of that recessive trait, chances are that it has disappeared from the family gene pool completely.
2007-01-29 14:45:35 · answer #1 · answered by lirael1019 1 · 0⤊ 1⤋
if you define a gene as a particular sequence in your dna, then no it is very unlikely it will become 'extinct'. there are definitly traits that are selected against depending on the environmental conditions, and so people or animals harboring those traits don't survive as well and the gene therefore doesn't get passed on. the best example of this are those songbirds that were in london (i think). they used to have all these white songbirds. then the industrial revolution came along and there was a bunch of smog in the air, so the darker birds flourished because they blended in better and the white ones started to die off.
So, no. In one person or animal a gene wouldn't die off, but through the length of the species if a trait causes negative consequences to the survival it will likely become less abundant in the population
2007-01-29 22:45:27 · answer #2 · answered by Laura A 1 · 0⤊ 0⤋
The dominance or recessiveness of a gene has nothing whatsoever to do with its long-term survival, only the odds that the trait it encodes will be expressed.
I imagine a gene could die out if it became totally deprecated and unused for any purpose, but even then it would take a very, very, very long time -- probably in the billions of years. The genome of all living organisms, except maybe viruses, is dominated by "junk" genetic material that is completely unused.
2007-01-29 22:44:25 · answer #3 · answered by poorcocoboiboi 6 · 0⤊ 0⤋
Yes, they do become extinct. This can be from a genetic bottleneck / genetic drift.
Some deleterious genes will eventually be bred out of the gene pool.
...and, of course, when a species becomes extinct, its unique allele sets go with it.
2007-01-29 23:00:56 · answer #4 · answered by Anonymous · 0⤊ 0⤋
yes it can. humans have 2 chromosomes, but only one (randomly chosen) is passed down to the offspring, so if too few people carry the gene, and they do not mate too often, the gene will die out.
2007-01-29 22:44:00 · answer #5 · answered by Anonymous · 0⤊ 1⤋
well, according to the theory of evolution, they can. if the gene is not helpful to the survival of the species, it will stop being passed down eventually (better chances of dying out if the gene is disadvantageous for the species)
2007-01-29 22:43:37 · answer #6 · answered by Veer 3 · 1⤊ 1⤋