Evolution toward Intelligence

ASTR 1420

Lecture 6

Sections 6.5 & 12.2

Evolution of Human

• Traits of tree life transformed to good human skillso Grabbing branches dexterous handso Swinging among branches depth perception good

hand-eye coordinationo Good parental cares for youngsters

• Primates : having hands, hand-like feet, forward-facing eyes

• Common myth:

Apes

Human

Humanoid

• Numerous hominid species

• no “missing link” in human evolution

Toumai

Cultural & Technological

Evolution

• Dramatic changes cultural evolution : via transmission of

accumulated knowledge

• Cultural evolutiono is far more important than natural evolution..o accelerates over time

• Beginning a new trend? Technological evolution :

increased technology new discoveries more advanced technologies more discoveries!

• Active Evolution:o genetic engineeringo modern medicineo not limited by Darwinian evolution anymore…

• During the past 40,000 years, we did not make any significant evolutionary changes…

Is intelligence inevitable?

“No”o biology might be common…o we (human) are the only one with Technology in

the Universe (or at best, extremely rare)o over 3.5 Gyr of life, only 200 years of

technologyo our existence is due to some lucky events

evolutionary stress from “Snowball Earth” or mass extinction impacts…

no mammal domination if there was no asteroid impact 65 Myr ago.

“Yes”o evolutionary pressure for intelligence

(lions and gazelles)o even if there was no human, other

technological species might have emerged instead.

o Convergent evolution intelligence

Convergent Evolution

• Dolphins and Sharksstreamlined “torpedo-shape” body formgreater speed for better survival to catch preys

• Eye-sightso most multi-cellular animals can “see”o eyes evolved independently 8+ times!

• Flightso bats, birds, pterodactyls, some insects…

• Sonar (echolocation)o whales/dolphins, bats

acquisition of the same biological trait in unrelated lineages natural selection often produces analogous adaptations.

Bioluminescence

• It has evolved independently at least 40 times!

E. A. Widder (Science, 2010, 328, 704)

Bioluminescence has resulted from some intriguing evolutionary adaptations. (A) In the deep- sea anglerfish Linophryne

coronata, bioluminescence from the esca is bacterial in origin, whereas that from the chin barbel is an unidentified intrinsic chemistry.

(B) In the octopus Stauroteuthis syrtensis, its suckers are photophores.

(C) In the tunicate Pyro- soma atlanticum, luminescence originates from pu- tative bacterial endosymbionts.

Extra credit…

All crabs look quite similar… but DNA information tells us that they are from many different ancestors (from shrimps, lobsters, etc.). Crablike body and walking must be an outcome of the convergent evolution.

What’s the benefits of these traits?

Measuring Intelligence

• Encephalization Quotient (EQ) = the ratio of the actual brain mass to the expected brain mass of a typical animal that size

• Human : 7• Chimpanzee : 3• Dolphins : 2.5-4.5• Hippo : 0.27• Raptors : 5.5• Troodons : 5.8

Evolution of Intelligence

• A trend toward increasing intelligence?

• Factors encouraging intelligence• high, effective metabolism (2% body weight

uses ¼ of energy)• long period of parental care (to pass down

knowledge)• Natural selection on intelligence

o less vigilant gazelle prey to a lionoincreases intelligence of the whole gazellesless smart lions can’t get mealsincreased intelligence for both.

• intelligence comes with a costo high metabolism and handling heavy head.

If only for survival, for given limited resources, other capabilities are equally good? faster running, better fighting, etc.

Pass down accumulated knowledge to next generation!

http://www.youtube.com/watch?v=NeXg0M1KBG4

Female monkeys in a group of about 250 monkeys teach their youngsters how to floss (2009 March, Thailand)

Pass down accumulated knowledge to next generation!

http://www.youtube.com/watch?v=NeXg0M1KBG4

Dolphins are using ‘tools’, sea sponge, to protect their snouts.

New research shows a group of West Australian dolphins have taught each other to use sea sponges to catch fish for almost 200 years!

Are we (human) the only technological species on Earth?

Clever Monkeys (by BBC) : or search YouTubehttp://www.youtube.com/watch?v=SSVF4CuXYno&list=PLD18C4AAD28D475E5

Technology: inevitable?

• A pathway from higher brainpower to science and technology seems apparent…

• For technology, there are some other needed traits (e.g., dexterous hands)o dolphins : with intelligence and social structure.

need to manipulate complex tools!!

• Even for advanced civilizations, do they head toward interstellar radio communications or space travels?

Need to find an evidence of alien technology on other habitable worlds!

In summary…

Important Concepts• Cultural evolution• Technological evolution• Woodpecker’s niche

Important Terms• Convergent evolution• Encephalization Quotient

Chapter/sections covered in this lecture : 6.5 & 12.2