Adaptations and Classifications: Is There a Connection?

A powerpoint presentation to follow “natural selection”

*

Adaptation

: any trait that aids the chances of survival and reproduction of organism •“variation” and “adaptation” not the same: •“

variations

” are raw materials upon which natural selection acts •“

adaptations

” are products of natural selection; aid survival and over time, all members of population inherit

*Adaptations are produced slowly– small changes or modifications over time; slight variations in traits of previous generation that helped organism survive

*TYPES OF ADAPTATIONS:

1. STRUCTURAL:

deal with anatomy- usually aid in feeding ex. Shape of beak or tooth

2. PHYSIOLOGICAL/ BEHAVIORAL:

functions in organisms deal with *

physiological:

adaptation with chemical basis associated with org’s function; ex. Spider’s web, clotting of blood *

behavioral:

result from response of org. to external environment ex. Migration, plants grow toward light

*for the next few slides, determine what adaptations are present.

Anybody know why the pufferfish “puffs” up?

*Knowing what we know about adaptations, does this separate animals into distinct groups?

YES!

*

SPECIES:

group of organisms that can interbreed and produce fertile offspring in nature *B/C mating between different species is rare, genes seldom pass from one gene pool to another.

*Why classify things?

*Biologists classify organisms in categories = taxa (taxon) *Purpose: to bring order to things; help identify unknown org’s *Also aids in naming organisms common names vary from country to country; scientific names don’t

HISTORY: Aristotle- 2 groups of organisms: plants, animals *Plants were classified according to size and structure *Animals were classified according to where they lived *Carolus Linnaeus (18 th century): system based on one characteristic: structural features *two org’s with same features- same species *BINOMIAL NOMENCLATURE: each organism is given a two-word Latin name: 1 st word: noun:

genus

to which organism belongs 2 nd word: adj: specific name Put together = species

*ex.: Cats belong to genus

Felis;

wildcat is

Felis sylvestris

while a house cat is

Felis catus

.

*Notice: first letter of genus is capitalized but species is not. Always underline or italicize scientific names.

DETERMINING RELATIONSHIPS: *Fossils used, homologous structures used *Biochemistry and development: studied embryos *Molecular basis: DNA!!!!!!!!!!!!

MOST ACCURATE TO DETERMINING RELATIONSHIPS!!!

*Compare N bases in DNA-- #’s and types; In other words, by studying base sequences, can determine how closely related organisms are

*

Phylogeny:

evolutionary history of organism based on fossil evidence, biochemistry, etc.

*Don’t panic, that’s as far down that “path” that we’re going to go…

System of Classification: A Pyramid of Information *Seven taxa form a series: *KINGDOM (BROADEST) *PHYLUM *CLASS *ORDER *FAMILY *GENUS *SPECIES **EACH OF THESE CAN ACTUALLY BE SUBDIVIDED (i.e. “subspecies” are breeds or varieties)

KINGDOM PHYLUM CLASS ORDER FAMILY GENUS SPECIES

EXAMPLE: Taxon: Kingdom Phylum Class Order Family Genus Species house cat Animalia Chordata Vertebrata Carnivora Felidae

Felis Felus catus

dog Animalia Chordata Vertebrata human Animalia Chordata Vertebrata Carnivora Canidae Primates Hominidae

Canis Homo Canis familiaris Homo sapiens

Most biologists use 5 Kingdom approach: 1. Animals 2. Plants 3. Monerans 4. Protists 5. Fungi *Reasons for more than just Plants vs. Animals: *Many microorganisms and others have characteristics of both Ex. Where would mushrooms fit? Don’t move like plants but aren’t autotrophic (photosynthesis) *Helps to identify if eukaryotic or prokaryotic

All organisms prokaryotic Monerans usually unicellular Protists eukaryotic multicellular autotrophic Plants heterotrophic Absorbs food Ingests food Fungi Animals