BioDiversity Set 2 - BIOLOGY AND ITS HISTORY

What is the definition of Biology?

It is the science of life/living things

Living things…

• Have one/many membrane-bound cells (the most basic unit of life) → Can produce other organisms like itself

• Can acquire and use energy

AUTOTROPHS are…

Plants, protists, and few bacteria

• Can produce their own energy (photosynthesis, chemosynthesis)

HETEROTROPHS are..

Animals, fungi, bacteria, and some protists

• Can take energy from other organisms (living or dead)

MIXOTROPHS can…

Both produce and take energy!!

Do living things evolve? (change over time)

YES - particularly for populations of a given species

What did Plato believe in?

He acknowledged diversity; however, every organism was a “perfect essence.”

• Had Typological thinking = each organism represents an unchanging type 

• Viewed variation as unimportant

Who created the scale of nature?

Aristotle

• Used a range of variables, size, complexity, and perception of advancement to create this scale

What did Aristotle believe in?

Like his teacher, he viewed organisms as unchanging over time = typological thinking

• Attempted to organize diverse life, using a range of variables, size, complexity, and perception of advancement

• Viewed variation among individuals as unimportant relative to the progression of life

Who first developed a hypothesis that addressed change & variation among organisms over time?

(Did not follow typological thinking)

Lamarck

Lamarck proposed what?

That change occurred through a phenomenon called “inheritance of acquired characteristics.”

• Individual organisms change during their lives, acquiring variability during their lives →This variability was passed on to their offspring

MODIFIED the scale of nature - organisms could move up the scale as they changed/evolved

Is Lamarck’s proposal of “inheritance of acquired characteristics.” accepted?

NO!!!!!

Evolution and Variability do not work this way, and never will - except for certain single-celled bacteria

Who proposed that organisms change over time, relevant to specific traits/ characteristics?

Darwin and Wallace.

They believed that:

• These types are NOT unchanging

• Similarities among different species may have come from common ancestors

• Proposed a testable mechanism where change over time could lead to new variations of a given species. OR production of a new species.

What is the official name of the testable mechanism proposed by Darwin and Wallace?

The DARWIN-WALLACE Theory of Evolution by Natural Selection

aka: Natural selection

How did Natural Selection evolve as a proposal?

1. Started with MANY observations/data from around the world

2. Generated the hypothesis of how natural selection might lead to the diversity of life

3. Over time, the hypothesis evolved into a theory due to LOTS of independent evidence

This image is an example of…

Lamarck’s Theory of Evolution.