Natural descent is basically another term for generations (as in a family-line). Legal descent is a term that deals with inheritance rules that were established to describe what happens if someone passes away and leaves no legal will.
Ascent is an antonym of descent.
tracing descent through the mother.
True.
speciation
"Rate of descent" is a speed; so the idea is to divide the distance by the time.
natural descent
No, it's the other way around: descent with modification is what you need for natural selection to happen.
Natural descent is a child that is born naturally through the will of male and female reproduction. Unnatural descent may be those born through a surrogate, or through in-vitro fertilization.
generations
He explained them in terms of descent with modification, common descent and natural selection.
One was Darwin's theory was the process of evolution by natural selection and the second one was Lyell's theory was that animals can adapt and change their traits to fit the environment.
natural selection and common descent
A fascination with the natural world, animals and plants and geology and his major discovery, his hypothesis of Natural Selection and Evolution of Descent with Modification!!
Individuals within a population have differences.
That evolutionary theory is accurate, at least in its fundamental theses: common descent and natural selection.
Common descent best demonstrates the unity of among all living organisms, not natural selection.
Darwinian evolution is descent with modification and natural selection, or, in other terms, reproductive variation and differential reproductive success.