1. Chap 24 Origin of Species

2. Changes within a species

3. Accumulation of changes leading to a new species Branching evolution which results in more species and more diversity

7. If closely related species become SYMPATRIC or if ALLOPATRIC species start to hybridize and exchange genes they will become ONE species again. If species are to remain as separate species, then they must develop INTRINSIC REPRODUCTIVE ISOLATING MECHANISMS to prevent gene flow and remain separate If species are to remain as separate species, then they must develop INTRINSIC REPRODUCTIVE ISOLATING MECHANISMS to prevent gene flow and remain separate

8. Ecological Species Definition: if there is no gene flow between two populations because they prefer different parts of the ecology or habitat, they are considered separate species.

10. Temporal Isolation

11. Sexual selection

14. Artemesiae and nebrascensis are considered PARAPATRIC SUBSPECIES although they live in adjacent areas they don’t mate, however there is still gene flow between the subspecies through matings with borealis and sonoriensis Artemesiae and nebrascensis are considered PARAPATRIC SUBSPECIES although they live in adjacent areas they don’t mate, however there is still gene flow between the subspecies through matings with borealis and sonoriensis

15. Bonus: write a good pneumonic device to memorize this

16. Speciation starts off with EXTRINSIC ISOLATING MECHANISMS the populations are ALLOPATRIC p469 four conditions which favor allopatric speciation Speciation starts off with EXTRINSIC ISOLATING MECHANISMS the populations are ALLOPATRIC p469 four conditions which favor allopatric speciation

20. Gene flow is stopped or limited

21. 3 Things that will cause the populations to form subspecies: 1.Different selection pressure. 2.Different mutations. 3.Different starting gene frequencies (founder effect) 4.Small populations may be subject to genetic drift (random change in gene freq.) 5.If the area is relatively unexploited, adaptive radiation may occur.

23. Some races may become so specialized that they no longer interbreed with races

24. A ring species range is so large that it circles back on itself – some ranges may circle around the earth

25. No interbreeding between the extremes of the cline

31. Because of sexual selection B and C don’t mate Because of ecological competition B and C become more different from each other.

32. This process can occur many times as long as the ecology can support the different types of birds this results in adaptive radiation.

33. 1.How many different species descended from the species that colonized the first island? Identify them. three; B, C, and D

34. 2.Why is species A no longer present on these islands? How is that change different from what happened to species B? Species A evolved into species B and no longer exists as a separate species. Species B is the common ancestor of species C and D, and it continues to coexist with the two newer species.

35. P471 Adaptive Radiation- flurries of allopatric speciation p451 four conditions which favor allopatric speciation

37. Adaptive Radiation the evolution of diversely adapted species from a common ancestor upon introduction to new environmental opportunities Dubautia laxa Dubautia waialealae KAUA'I 5.1 million years O'AHU 3.7 million years LANAI MOLOKA'I 1.3 million years MAUI HAWAI'I 0.4 million years Argyroxiphium sandwicense Dubautia scabra Dubautia linearis N 21.5

41. The bright yellow and red- crowned Yariguies brush-finch was found in a remote Colombian cloud forest.

44. P 473

45. SYMPATRIC SPECIATION Autopolyploidy- same species forms new sp Oenothera lamarkia 2N=14 Oenothera gigas 4N=28 SYMPATRIC SPECIATION Autopolyploidy- same species forms new sp Oenothera lamarkia 2N=14 Oenothera gigas 4N=28

46. Allopolyploidy- two different species mate to form polyploid hybrid S. martima 2N=60 S. alternaflora 2N=62 S. anglica 2N=122 Allopolyploidy- two different species mate to form polyploid hybrid S. martima 2N=60 S. alternaflora 2N=62 S. anglica 2N=122 There are different ways for allopolyploidy to occur P 474 Odd # of chromosomes Meiotic error

48. Eldridge and Gould Darwin 476

50. Evolution of the Genes That Control Development Genes that program development –Control the rate, timing, and spatial pattern of changes in an organism’s form as it develops into an adult 21.8

51. Allometric growth –Is the genetically controlled proportioning that helps give a body its specific form Newborn 2 5 15 Adult (a) Differential growth rates in a human. The arms and legs lengthen more during growth than the head and trunk, as can be seen in this conceptualization of an individual at different ages all rescaled to the same height. Age (years) 21.8

52. Allometric Growth difference in the relative rates of growth of various parts of the body help to shape the organisms Allometric Growth difference in the relative rates of growth of various parts of the body help to shape the organisms Paedomorphosis- Changes in developmental timing ex: human brain is larger because growth of brain switched off much later than chimps Paedomorphosis- Changes in developmental timing ex: human brain is larger because growth of brain switched off much later than chimps Heterochrony temporal changes in development lead to evolutionary novelties Heterochrony temporal changes in development lead to evolutionary novelties Timing of growth effects the shape, development and evolution of organisms Small changes in timing can lead to large phenotypic change

53. Different allometric patterns –Contribute to the contrasting shapes of human and chimpanzee skulls Chimpanzee fetus Chimpanzee adult Human fetus Human adult Comparison of chimpanzee and human skull growth. The fetal skulls of humans and chimpanzees are similar in shape. Allometric growth transforms the rounded skull and vertical face of a newborn chimpanzee into the elongated skull and sloping face characteristic of adult apes. The same allometric pattern of growth occurs in humans, but with a less accelerated elongation of the jaw relative to the rest of the skull. 21.8

54. Homeosis-Change in the basic bauplan (body plan) of the organism This can be accomplished with genes that act as Master Switches like homeotic genes Homeosis-Change in the basic bauplan (body plan) of the organism This can be accomplished with genes that act as Master Switches like homeotic genes Duplication of the Hox homeotic genes led to vertebrates One gene that controls for one segment can be duplicated and modified to control for another segment

56. Exaptation genes take on different functions in another context Exaptation genes take on different functions in another context

57. Species Selection The species that endures the longest and generates the greatest number of new species determine the direction of an evolutionary trend differential species success Species Selection The species that endures the longest and generates the greatest number of new species determine the direction of an evolutionary trend differential species success