0
Answer 1
Usually new species evolve from a common ancestor when, for some reason, there develops a decline in the frequency of interbreeding between two groups within the ancestral population. The decline in interbreeding causes increasing genetic divergence between the two groups, which in turn may act to further diminish the interbreeding frequency, which in turn leads to further divergence, and so on. If this continues, then eventually the interbreeding frequency between the two groups drops towards zero (or very nearly anyway), and would remain zero even if the two groups were put back together, and speciation can be said to have occurred.
There may be various causes for this decline in interbreeding. The mechanism that is simplest to explain is geographical isolation of two populations. Natural disasters or migrations, for instance, may cause two subpopulations of the same species to become separated from one another, so that interbreeding no longer takes place, and divergence can occur unimpeded. But there are also ways for divergence to occur in sympatry: between two groups occupying the same habitat.
Answer 2
According to DNA studies every biological event that causes changes to a species is from genetic losses and deleterious mutations.
You can see from early evidence that the oldest of any now living creature was far more complex and appears to be more fit for far more difficult environmental circumstances.
We have nearly 90% of the now living or recently extinct, non bird vertebrate, creatures as fossils. None of them appear to have crossed any lines of genus nor does their morphology appear so different that they are not recognizable as the same genus.
And we can see transitions back to these far more fit creatures. The Saber Toothed tiger degenerated and speciated to produce many of the cat lineages we have now. The path way of evolution is actually degeneration.
As creatures develop more and more genetic defects from mutation they are unable to breed when they are separated by land movements or like some modern mice by being dropped off a ship onto an island. There are also atavism which seem that if they are triggered by the environment like the Italian wall lizard was able to bring up an old gene (atavism) used to process vegetation and use that because the normal non-vegetable foods were sparse in this "new location".
It is this degeneration away from the parent species and the degeneration of the parent species that separates and stops reproduction.
The Chicken is said to have been from the "dinosaur" lineage and if you look at dinosaurs it is clear they were far more fit to survive in severe environments. The chicken has lost its teeth and shows in DNA teeth as an atavism. Scientists have been able to "trigger" that atavism and produce chickens with teeth.
In every case there is only degeneration shown in all DNA compared to the physical evidence.
In DNA studies on humans we have never found even on beneficial mutation to offset the 50,000 deleterious ones (estimated total to be about 100,000 world wide) we have amassed by our lifestyle choices.
There are certain types of (tribes of) human right now that have trouble reproducing. In the future as their mutations get them farther apart they will have a new species of human to deal with and have to come up with a new name, like "AlosHumans" or something to describe them as a separate species.
The chimpanzee is an amazing phenomenon that shows this very well. It is estimated from DNA and from ancient artifacts that chimps speciated from the human lineage about 4000 to 7000 years ago at best estimate. (There are no fossils of chimps indicating a small tribe and young tribe.)
The chimp is degraded to the point of extinction. If humans did not put them in preserves there would be none left. They are not smart enough, nor healthy/adaptable to defend themselves from human predictors, like moving up high in the mountains, to get away from humans and they don't reproduce but max of 3 baby chimps per female and 2 out of 3 die.
The process of (evolution) degeneration is clear, there are only 800 left in the wild and the rest are in cages or on preserves.
Our cousins apparently degenerated by 1/ mutagenic activities producing more and more diseases that attack them at the fetus level at the germ line and 2/ possibly move to an area with radiation or some toxin that caused these mutations that are destroying them.
Chimps should be a message to us about how we need to protect ourselves from spreading diseases, and causing more and more human suffering from our ignorance about how we are made.
Answer 3
Humans and other organisms are evolving not devolving. MRSA is an example of this. This is a normal skin microbe that has evolved the ability to not be affected by many antibiotics.
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
The emergence of many diverse species from a common ancestor that finds itself in a new environment is called?
adaptive radiation- I'm sure its correct. I just entered that answer in my "masteringbiology" hw. good luck :)
What relationship would my first cousin's child be to my grandchild?
They would be second cousins, once removed. The descent is from a common ancestor. Thus 1st cousins share a grandparent as a common ancestor. 2nd cousins share a great-grandparent as an ancestor. If the descent from the common ancestor is not an equal number of generations, the inequality is expressed as 'removed' from the oldest generation being compared.
Mimbership in a mongol clan was determinded bt the members claim of a common?
Ancestor.
How are your great aunt's grandchildren related to you?
Your great aunt's grandchildren are your second cousins because you share a great grandparent. Your great aunt's great grandchildren are your second cousins, once removed, because you share the same common ancestor but are one generation differently removed from that ancestor. You are the third generation from that common ancestor, while they are the fourth generation.
Are Aleister Crowley and Barbara Bush related?
Apparently not, although they may have had a common ancestor centuries ago.
How might evolution theory account for this phenomenon?
Evolutionary theory can account for the phenomenon of a new species. This is because different species can evolve from a common ancestor.
What does it mean when two species share a common ancestor?
An ancestor.
Similar structures that related species have inherited from common ancestor.?
what is Similar structures that related species have inherited from a common ancestor
When the internal strucure of two species are very similar what can be inferred about both species?
They evolved from a common ancestor.
Why does Darwin use a tree as a model for the evolution of animals?
Darwin used a tree as a model for the evolution of animals to represent the divergence of species from a common ancestor. Just as branches on a tree diverge from a common trunk, species evolve and diverge from a common ancestor through natural selection and adaptation. This visual representation helped illustrate the concept of common ancestry and the branching of species over time.
A species from which two or more species diverged?
Common ancestor
What is speciation ?
the formation of species
What is a common ancestor?
a common ancestor is a species that multiple species share as the species they descended froma person born or that has lived before you and the word common means the same SO ....... its when you have the same descendant or person who lived before you or an ancestor that's the same
What is an apical ancestor?
An apical ancestor is the most recent common ancestor of a group of species in a phylogenetic tree. It represents the point where the evolutionary lineage leading to a group of species splits from the rest of the tree.
How many years did it take for a chimpanzee to turn into a human?
Humans did not evolve from chimpanzees, but both species evolved from a common ancestor.
Should species that have evolved from a common ancestor have certain characteristics in common?
true.
Species that have evolved from a common ancestor should have certain characteristics in common?
true.
