MACROevolution vs MICROevolution - what is it?

There are two goals when helping a species recover from a population bottleneck: 1) Increase the numbers in the population to reduce the threat of extinction and to restore it to healthy maintainable levels; 2) increase the genetic diversity. In the case of the Florida panther there is only the single population in southern Florida. Individuals from other populations cannot be introduced to increase genetic diversity. Gaining beneficial mutations is very unlikely on a human timescale except for species with very, very short generational periods, like bacteria. New varieties can be created by reduced genetic diversity, but not new species. New breeds would still have all the same genes and alleles as the original population and could still breed with them. They could never be a new species.--Percy

Sure they do, just not usually on an observable human timescale. I did come across information that some Texas pumas were introduced into the Florida Panther population to increase diversity, and that was helpful. Elephant seals have one pup per year, while the Florida panther has 2-3 kittens every two years. Without mutation, even many generations of inbreeding would create no new genes or alleles. The inbred subpopulation would still possess only genes and alleles already found in the main population. They would be the same species.--Percy

Not a single one of these questions belongs in this topic.--Percy

Where on Earth did you get the idea that genetic depletion means inability to breed with other members of the same species? The Florida panther is a cougar, and cougars can breed with each other. The various populations of cheetah spread around the world can breed with each other. Because, like, they're the same species and all. You can't get a new species just by manipulating gene frequencies - that just results in new breeds. It's why breeders can't create new species. Only over long time periods are enough mutations produced and distributed to result in the genetic incompatibility that truly defines a new species. A single mutation is microevolution and would be unlikely in the extreme to produce the significant change necessary for speciation. Macroevolution is the accumulation over time of many mutations sufficient to produce new species. No one is suggesting or has ever suggested that fur color by itself defines a new species.--Percy

That's because cheetahs and other cats are different species. As cheetahs lose habitat to human expansion their numbers are dropping along with their genetic diversity. This loss of genetic diversity is not causing any speciation - in fact, the uniformity of cheetahs is notable. Of course a mutated allele can behave differently from the original. An allele is a template for a protein. When an allele changes then the protein may change, and when the protein changes it affects the organism. A mutation that is not passed on to the next generation is certainly lost, but there is nothing to prevent its being passed on unless it negatively affects the organism's ability to reproduce.And a mutation is most certainly microevolution because it affects the gene frequency in the population. The original allele's frequency is less because a new allele now exists. If an organism reproduces then obviously it was selected. Having a mutation is not a sterilizing event. Humans average around 100 mutations each, and the vast majority of us are not sterile.And of course speciation isn't going to happen from a single mutation. That's why it's microevolution. And yet, as I said before, breeders are unable to produce new species. Except that it does. There is nothing that could stop the occurrence of mutations with every reproductive event. Mere loss of genetic diversity does not create new species. Again, that's why breeders cannot produce new species. Just using selection to remove alleles from a subpopulation leaves the breeder with the same species, albeit a population with characteristics he emphasized. It takes time for the accumulation of sufficient mutations to form a new species. Nobody said it wasn't. That you keep thinking nobody grasps this indicates some gaping hole in your understanding of what people are saying. That's only one of the possibilities. Selection can result in alleles at any frequency level. Speciation by mere reduction in genetic diversity never happens. All it takes is for the rate of acceptable mutations to exceed the rate of loss of alleles.--PercyEdited by Percy, : No reason given.

You can create a link to a message by entering "[msg=580]". If you do that then you'll get this link to message 580: Message 580.By the was, there's a rule in the Forum Guidelines that sort of requests you not compose messages consisting of little more than a link:

5. Bare links with no supporting discussion should be avoided. Make the argument in your own words and use links as supporting references.

It is also often suggested that you reexplain arguments rather than referencing previous messages that weren't understood the first time they were read.--Percy

Unless the new population is a family group, "inbreeding" would not be the correct term to use for "breeding within the new population." "Inbreeding" is about mating between closely related individuals. The mutations that accumulate over time to form a new species are unlikely to be deleterious, because that would make the population less fit. It's not pedantic or irrelevant. HereBeDragons was responding to your assumption that genetic incompatibility is necessary to produce a new species. He used the example of the ring species Greenish Warblers. Though individuals at opposite ends of the ring may not be genetically incompatible, they may not recognize each other as mates and so are reproductively isolated. Speciation is not solely dependent upon the failure of gametes to fuse.--Percy

HBD was agreeing with you - that's why he began his paragraph with the word "Exactly."But he went on to explain again the great utility of his RIL example, that it achieves your goal of diminished genetic variation far faster than your daughter population example. And the end result? No speciation. Some animals self-fertilize, some change sex, some do both. HBD is just emphasizing in different terms what he just said. The "fixation of alleles" part is about reduced genetic variation, and "homogenization" you already understand because you've been using that term yourself. HBD is explaining why your claim that reduced genetic diversity causes speciation is wrong. The RIL example produces reduced genetic diversity and homogeneity much faster than any breeder (and much, much faster than the wild) could achieve, yet still fails to produce new species.--Percy

Faith is merely employing her time-honored strategy of insult and provocation when discussion doesn't go her way.I *do* think your RIL example is worth plugging away at. There were a few bits of it that I thought Faith might find challenging, but none it seems like it should be beyond her.--Percy

Mutations don't just "show up here and there." Mutations occur in all offspring of all populations. It will be very, very rare when that is not the case. Generally, yes, the mutations each offspring experiences will be different from other offspring. (Though some mutations occur repeatedly, for example, the mutation that causes Down syndrome. The extra copy of chromosome 21 occurs by chance. This is, of course, a deleterious mutation.) I don't think you want to trivialize the definition of phenotype to the point where each individual in a population is its own phenotype. If a mutated allele produces a slightly different protein that does pretty much, but not exactly, the same thing as the original protein, is that a new phenotype? If a mutation causes a slightly different blood type, is that a new phenotype? If you begin answering, "Yes, that's a new phenotype," too often to these types of questions then pretty soon you'd have to begin considering a population to have just as many phenotypes as individuals. Right, that's not a new species. A single active mutation cannot cause speciation (polyploid speciation, where the entire chromosome set is duplicated, is a rare exception). A single active mutation will not even usually cause new or different traits. It usually takes an accumulation of active mutations over time to cause changes that are observable by anything other than protein analysis. Reproduction is what spreads mutations. Selection and mutation are simultaneous processes. Selection decides which individuals contribute their genes to the next generation, and virtually all offspring of every generation have mutations. Yes, agreed so far. Loss of genetic diversity leaves you with a population that only has genes and alleles already present in the parent population. There is nothing to genetically distinguish them. That's true, but in the wild species do not remain stable. I'm glad you included mutations in your list. Evolution includes both change (mutation) and selection. We're in the middle of it here.--PercyEdited by Percy, : Grammar.

Maybe you should get a stress ball instead of making other people the target of your frustrations. It was very relevant, as has been explained. An RIL strain has extremely little genetic diversity, far less than a daughter population or a breeder could achieve, and yet no matter how many of them you produce you never get a new species.--Percy

This is just an empty redeclaration of your position, and it is wrong. It is obvious that the species in the world today are genetically distinct, most to the point of reproductive incompatibility. Being genetically distinct from one another is one of the primary observed qualities of existing species. Since adding new genes and alleles to a daughter population would make it genetically distinct, that is what you need to do to create a genetically new species.A population with reduced genetic diversity would possess all the genes and alleles already present in the parent population. It could never be genetically distinct from the parent population.--Percy

I think rereading HBD's posts will go a much longer way toward understanding what he is saying than watching population genetics videos, but anyway, which videos are you watching? That's the whole point of HBD's RIL example, to eliminate as much genetic variability as possible in as few a number of generations as possible, far faster than breeders or daughter populations in the wild. And yet despite RIL's extreme loss of genetic diversity, no speciation.--Percy

You're just repeating your position again, still absent any evidence or argument that can hold water or make sense. Regarding inability to breed with other populations of the same species, inability to breed is the very definition of different species. If two populations can't interbreed then they're not the same species. Gradually accumulating genetic differences in separated populations is what brings about speciation. This is obvious because genetic distinctness is what defines all the species that exist in the world today. Differing allele frequencies do not define species, different alleles and genes do.--Percy

Where were you the first 117 times this was explained?Mutations occur in every generation. Those that are neutral or beneficial are passed on to the next generation, and the next and the next and the next and onward through time. Gradually these mutations accumulate and spread throughout the population. Separated populations of the same species would acquire and accumulate different mutations and gradually become increasingly genetically incompatible. Your scenario can never reach the point of genetic incompatibility. The daughter population can only possess genes and alleles already genetically compatible with the parent population. You can't get different alleles in your scenarios because you allow no role for mutation. In your scenarios a daughter population can only have alleles the parent population already has. And in your scenarios a daughter population can certainly never acquire new genes, and differing genes is the most distinct difference between most species. New genes are often copying errors, just like new alleles are copying errors. New genes come about in various ways. A new gene may be formed by gene duplication, where a gene is copied twice instead of just once during gamete formation. Or small mutations could create start/stop codons in a previously inactive region of the genome. Or start/stop codons could mutate to something else, resulting in one gene becoming two, or two genes becoming one, or a sequence of previously inactive DNA being added to an existing gene. Lateral gene transfer might introduce a gene from another species. Or viruses might insert a new gene. Any offspring experiencing a mutation rendering it meaningfully less fit will not likely pass its genes on to the next generation. Selection filters out deleterious alleles and genes before they affect the population.Gene duplicates are especially easy to detect, and there are many examples. It is estimated that the human lineage has experienced 100 gene duplicates per million years (Origins of New Genes and Pseudogenes). The most familiar example of gene duplication is actually duplication of an entire chromosome with all its genes: Down syndrome. Many plants contain examples of duplication of their entire genomes (polyploid speciation). Ice fish have a gene duplication that provides an antifreeze capability (Gene Duplication), and snakes have a gene duplication that helps provide snake venom (Inventing an arsenal: adaptive evolution and neofunctionalization of snake venom phospholipase A2 genes). The similar MWS/LWS genes in primates arose through gene duplication and provide improved color sensitivity for eyesight (Evolution of colour vision in primates).--Percy