22Mar-PL-Speciation (1)

22Mar-PL-Speciation (1) - Speciation The Concept of Species...

Info iconThis preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Speciation The Concept of Species A species is the smallest fundamental unit of taxonomy of plants & animals. Species members share a gene pool (they are capable of interbreeding to produce fertile offspring), & are reproductively isolated (cannot mate with other species) They very closely resemble each other. The definition of a species depends on the following attributes : Morphological Similarity They look alike. Physiological Compatibility They function alike. Ecological Association They live in similar conditions. Geographical Distribution They can tolerate similar conditions/environments, e.g. climate. They have Continuity in Time They live at the same time. Theoretically a species cannot naturally interbreed successfully with another species (reproductive isolation). But obviously this does happen: dogs & wolves, dogs & coyotes (coydogs) , bison & domestic cattle (beefalo), Various types of mice & voles have bred without human intervention. In zoos & on farms other species have bred: Tigers, jaguars & lions (Tigrons, Jagrons, Ligers), horses & donkeys (Mules & Hinnys), camels & llamas (camas). Beefalo. Chausie & Bengal cats have been bred from domestic cats & jungle cats, Asian leopard cats & Servals. Some of these Hybrids have broken Haldanes Law & produced fertile young. So either our definition of a species is wrong or our understanding is incomplete. < Liger Tigron > < Beefalo Bull Cama > zonkey Mule (male donkey /female horse) Hinny (male horse/female donkey) Zorses < Geep Coydog > < Dolf Groler bear Poler/grizzly X Wild Duck hybrids: left & middle: Mallard (Anas platyrhynchos) Northern Pintail (Anas acuta) X & right: Eurasian-American Wigeon X (Anas penelope, Anas americana). Mallards hybridize more than any other species of duck even crossing genus lines (50 other species of duck & geese): merganser, eider, mandarin, wood duck, redhead, ring-necked duck, tufted duck, canvasback, domestic waterfowl, feral ducks, e.g. Mallard- Aylesbury Xs The scientific name for a species is an italicized binomial in which the species name is preceded by the name of the genus. The name is succeeded by the name of the authority who named the species. Trinomials are used for subspecies. Aylesbury Duck (domestic) & Mallard-Aylesbury Xs male & female E.g. Modern Humans Homo sapiens , Linne 1758 There are two subspecies: Homo sapiens neanderthalensis , King 1864 (Neanderthal Man) Homo sapiens sapiens , Linne 1758 (Anatomically Modern Man) [Neanderthal & Modern Human DNA differs by ~0.5%] Recent DNA work has shown that humans share 95-99.4% of their DNA with Chimpanzees & Bonobos ( Pan troglodytes & Pan paniscus ) & some suggest that these species should be included in the genus Homo . DNA distance to other primates (%) :- Humans & Bonobos 1.64 Humans & Gorillas 2.27 Humans & Orang Utans 3.60 Humans & Gibbons 4.76 Humans & Chimpanzees ~5.00 Humans & Primates are now considered Hominids while...
View Full Document

Page1 / 128

22Mar-PL-Speciation (1) - Speciation The Concept of Species...

This preview shows document pages 1 - 14. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online