1. Speciation

2. Speciation in Darwin’s Finches
Speciation in the Galapagos finches occurred by founding of a new population, geographic isolation, changes in the new population’s gene pool, reproductive isolation, and ecological competition.

3. Founder’s Arrive
Finches from the mainland of South America arrive on the Galapagos islands.
As finches do not usually fly over open water, it is assumed they were blown off course by a storm.

4. Separation of Populations
As finches do not fly over open water, they remained on whatever island they landed on.

5. Changes in the Gene Pool
Each island of the Galapagos has its own unique flora and fauna (plants and animals)—the finches slowly adapted to their islands through natural selection.

6. Species
A species is a group of organisms that breed with one another and produce fertile offspring.
This population will share a common gene pool.

7. Reproductive Isolation
When members of two populations cannot interbreed and produce fertile offspring,

8. Behavioral Isolation
Occurs when two populations are capable of interbreeding but have differences in courtship rituals or other reproductive strategies.

9. Geographic Isolation
Two populations are separated by a geographic barriers such as rivers, mountains, or bodies of water.

10. Temporal Isolation
Two or more species reproduce at different times.

11. Ecological Competition
All organisms compete for limited resources.
The finches evolved specialized beaks for particular foods to limit the competition.

12. Continued Evolution
The process of isolation, genetic change, reproductive isolation, most likely repeated itself over and over again.
As a result, there are 13 different species of Galapagos finches.

13. Human Evolution

14. Primates
The evolutionary history of primates began about 85 million years ago.
Fossils have been found primarily in North America, however they were widespread throughout Eurasia and Africa
Notharctus
Discovered in Germany
~ 16.5 million years old

15. Primates to Humans
Nakalipithecus (Kenya) & Ouranopithecus Ouranopithecus (Greece)
Last common ancestors between gorillas, chimpanzees, and humans.
Between 8-4 mya, chimpanzees and gorillas split from the line leading to humans.

16. Becoming Human Savannah Theory Aquatic Ape Hypothesis
Proposed by Raymond Dart
Stated that hominids began to stand on two legs to peer over savannah grasses to hunt and hide from predators.
Aquatic Ape Hypothesis
States that early hominids lived around water and often dove, waded, and swam.
Accounts for our lack of hair, subcutaneous fat, and abundance of sebaceous glands.

17. Hominids Homo habilis 2.4 to 1.4 million years ago (mya)
Found in Africa
Possessed small molars and large brains
Was surrounded by stone and bone tools
Nicknamed “Handy Man”

18. Hominids Homo rudolfensis and Homo georgicus 1.9-1.6 million years ago
H. rudolfensis
Incomplete skull found in Kenya. Scientists debate whether this is another species, or another H. habilis
H. georgicus
Found in Georgia (near Russia)
Thought to be an intermediate form between H. habilis and H. erectus

19. Hominids Homo ergaster and Homo erectus H. ergaster H. erectus
Discovered in Indonesia
mya, seen as a subspecies of H. erectus
H. erectus
1.5-1 mya, found in Africa, Asia, and Europe
Used elaborate stone tools
First human ancestor to truly walk upright
May have used fire
Peking Man

20. Hominids Homo cepranensis and Homo antecessor
Both thought to be intermediate forms between H. erectus and H. heidelbergensis
H. cepranensis
1.2 mya-500,000 ya
Based on fossils found in Spain and England
H. antecessor
800,000 ya
Based on a single skull cap found in Italy

21. Hominids Homo heidelbergensis lived from 800,000 ya to 300,000 ya
Heidelberg Man

22. Hominids Homo rhodesiensis Gawus Cranium
300, ,000 ya—disputed separation from H. Heidelbergensis
Rhodesian Man
Gawus Cranium
Discovered in 2006 in Gawis, Ethiopia
500, ,000 ya
Might possibly be an intermediate species between H. erectus and H. sapiens

23. Hominids Homo neanderthalensis 300,000 ya to 30,000 ya
Mitochondrial DNA studies suggest that H. neanderthalensis is a separate species from H. sapiens
Neanderthals are NOT our ancestors

24. Hominids Homo sapiens 250,000 ya to the present
Direct evidence suggests we migrated out of Africa
However, this does not preclude multiregional speciation
H. sapiens idaltu
Oldest known anatomically modern human
160,000 years old, found in Ethiopia

25. Hominids Homo floresiensis 100,000-12,000 years old
Skeleton of a 30 year old woman found (~18,000 yo)
One meter (3 feet) tall
Nicknamed “Hobbit”

26. Hominids Homo floresiensis Separate Species or Homo Sapien?
At first scientists thought that H. florensiensis was a separate species
Now, they believe that H. floresiensis is a H. sapien that has insular dwarfism
Modern day people on the island of Flores are pygmies