Species Notes

7/26/2019 Species Notes

1/9

species

Monday, November 9, 2015

2:59 PM

Microevolution - occur over short time span

Tal about macro evolution over lon!er time span

"irst topic - is the ori!in o# species

Tal about natural selection and adaptation

$e#er to chan!es occur to particular species over time

Peppered moth #rom li!ht to dar coloration

%ne thin!s that is clear lots o# di&erent ids o# pecies

'o( did that happen

)hat is responsible #or ne( species

Title o# dar(ins boo

%ri!in o# species

*idn+t have a lot o# insi!ht on ho( they ori!inate

More in#ormation no(

oo at some bear - #amiliar (ith

lac bear, polar bear, bro(n bear

North america

lac bear - in united states

ro(n bear - composed o# subspecies - !ri..ley bear


2/9

Polar bear - in arctic re!ions

/losely related species o# bears

Names o# species

rsus americanus

rsus maritimus

rsus arctos

'o( did they come about

10 million years a!o

ome bear species ancesteral to all three

3n that point o# time

in!le bear species

plit and one linea!e (ent o& to become blac bear

4nd other split o& and split a!ain to #orm polar bear and bro(n bear - millionyears a!o

)hen (e have this ind o# speciation


3/9

in!le lina!e splits into 2 ho( does that happen

)hat does it mean to be a species

)hat maes a species di&erent than another

)hy are they di&erent #rom each other

%ne o# the reasons - di&erent bear species - loo di&erent

Polar bear - bi! (hite

ro(n bear - bi! bro(n

lac - smaller blac bear

een around a lon! time

Morpholo!ical species concept - one species loos di&erent #rom another

Morpholo!ical - (hat you loo lie

3# these thin!s loo the same one species - loo di&erent another species

Problems (ith this

Thin!s loo di&erent #rom each other but turns out they are closely related and maybe same species

$ecall (e taled about the #act that cauli6o(er, brussels sprouts, cabba!e - derrivedby arti7cial selection #rom mustard lie species

*i&erent species - but closely related and same species

$un into thin!s that loo di&erent that are closely related

ee thin!s loo similar and thin they are related to each other but aren+t

'o( similar 2 thin!s loo - can+t tell us ho( closely related they are

'o( to determine (hat species is

roadly accepted

iolo!ical species concept


4/9

)hat this concept emphasi.es

3nterbreedin!

3ndividuals members o# same species i# they can interbreed (ith each other

*i&erent species reproductively isolated #rom each other

8ene pools don+t mi

8ene pools - populations

3# (e have 2 populations that belon! to 2 di&erent species

8ene pools don+t mi

Three bear species

ro(n bears and blac bears can be #ound to!ether

Populations o# bro(n and blac bears consist o# !ene pools

ro(n bear !ene pool

lac bear !ene pool

lac bear don+t mate (ith bro(n bear

ro(n bear don+t mate (ith blac bear

/oncept evolutionary

Phylo!eny

"amily tree that results #rom speciation

till problems (ith this concept too

iolo!ical species concept

$eproductive isolation

*on+t interbreed (ith each other

'o( does this come about


5/9

)hy don+t they mate (ith each other

$eproductive isolation

*ue to di&erent species - very particular matin! behaviors

Matin! behaviors o# one species doesn+t tri!!er response in another species

4nother posibility di&erent species don+t mate at di&erent times or di&erent places

*on+t encounter each other

Matin! o# t(o may occur but o&sprin! is sterile and can+t mate (ith anythin! elseand have an o&sprin!

8ood eample is horse and doney to mae mule

irds !oin! throu!h head, nec, body motions

ittle matin! dance

Male initiatin! and #emale respondin! and male respondin!

"emale o# another species (ouldn+t respond to another species

'ybrid sterility

Matin! can occur bet(een t(o species


6/9

ust because t(o species mate doesn+t mean they belon! to same species

3nterbreed not same as mate

3nterbreed mate and produce o&sprin! (hich mate bac to either parentpopulations

Mule - product o# #emale horse and male doney

Mule - viable o&sprin!

/an live but can+t reproduce

*i&erence in number o# chromosomes in horses and doneys

'orse - ;

*oney - 2

Mule - uite come to!ether

/onsider pre.y!otic barrier

econd type - even i# matin! occurs

$e#er to those as post .y!otic barrier

?y!ote #orms sperm and e!! come to!ether

ut various reasions

nion never produces viable that can live

%r produces somethin! that can live - that thin! is sterile - such as mule

)hat it means #or one species to be di&erent than another species

'o( this split can occur

8o #rom one species to t(o species

'o( speciation occurs

%ne clue as to (hat mi!ht happen

in!le species over ran!e it occurs

ro(n bears - are #ound in (estern part o# united states and into alasa and europeas (ell

%ver ran!e- di&erences in bro(n bear

Montana - !ri..ley bear

4lasa - codiac bear

@urope - called somethin! else


8/9

oo di&erent

8eo!raphical variation

Many inds o# species - variation throu!hout their ran!e - (hy do they loodi&erent ocal adaptation

8ri..ley bear - di&erent than codiac bear in alasa

/hance can be part o# it as (ell

Ano( about these di&erences

8eo!raphic patterns by looin! at our o(n species

People livin! in di&erent places loo di&erent

Barients - subspecies that loo di&erent than each other - rat snaes

"ound in di&erent places

8eo!raphical variation means

'umans becomin! di&erent species

*i&erent varients o# rat snae - di&erent species

Not necessarily

4t this point - all o# these races and varients o# rat snaes


9/9

/an interbreed (ith each other

/an mate (ith each other

"or di&erent species - can+t interbreed (ith each other

8eo!raphical varients to becoem di&erent species

8ene 6o( - stop bet(een them

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