16 SEP 2011 by ideonexus
"Natural" Classification of Species as Evidence for Evolu...
Actually, the nested arrangement of life was recognized long before
Darwin. Starting with the Swedish botanist Carl Linnaeus in , biologists
began classifying animals and plants, discovering that they consistently
fell into what was called a “natural” classification. Strikingly,
different biologists came up with nearly identical groupings. This means
that these groupings are not subjective artifacts of a human need to
classify, but that they tell us something real and fundamen...Taxonomists working independently naturally "nest" species in the same groups.
16 SEP 2011 by ideonexus
Darwin Considers Intermediaries Between Species
I have found it difficult, when looking at any two species, to avoid
picturing to myself, forms directly intermediate between them. But this
is a wholly false view; we should always look for forms intermediate
between each species and a common but unknown progenitor; and
the progenitor will generally have differed in some respects from all of
its modified descendants.Folksonomies: evolution missing links
Folksonomies: evolution missing links
But recognizes that this line of thinking is misleading, because species have common ancestors that are something different from both their descendants.
16 SEP 2011 by ideonexus
DNA as Evidence of Common Ancestry
By sequencing
the DNA of various species and measuring how similar these sequences
are, we can reconstruct their evolutionary relationships. This is done
by making the entirely reasonable assumption that species having more
similar DNA are more closely related—that is, their common ancestors
lived more recently. These molecular methods have not produced much
change in the pre-DNA-era trees of life: both the visible traits of organisms
and their DNA sequences usually give the same informatio...The idea of common ancestry leads naturally to powerful and testable predictions about evolution.