L2: Anatomy & Evolution Flashcards

Learning Objectives: 1. Recognise phylogenies and understand where we sit in the phylogenetic tree 2. Understand how phylogenies are arrived at 3. Understand the we are chordates and the features that define this phylum 4. Know the major groups of vertebrates 5. Understand the differences between the vertebrates and other chordates 6. Understand the differences between jawless and jawed vertebrates 7. Understand the features that define us as tetrapods, amniotes and mammals

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1
Q

What is phylogenies?

A

Trace patterns of shared ancestry between lineages

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2
Q

What is a phylogenetic tree?

A

Graphical representation of evolutionary history

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3
Q

What is ontogeny?

A

The origination & development of an organism, usually from the time of fertilisation of the egg to adult

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4
Q

What is phylogeny?

A

Evolutionary history & relationships among a group of organisms

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5
Q

What kind of organisms will share more closely related genes?

A

Related organisms

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6
Q

What can be constructed using comparisons between gene sequences from different organisms?

A

Phylogenies

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7
Q

What was previously used to construct phylogenies?

A

Ribosomal RNA genes

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8
Q

What are chordates?

A

Animals with a flexible rod supporting their back

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9
Q

What were the new adaptations for vertebrates?

A

Complex CNS, paired sense organs

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10
Q

What was the evolution of vertebrates regarding jaws?

A

Went from jawless to jawed vertebrates

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11
Q

What were vertebrates able to do after the evolution of jaws?

A

Explore new ecological niches

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12
Q

How many nostrils in cyclostomes?

A

1

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13
Q

How many nostrils in gnathostomes?

A

2

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14
Q

Anatomical changes of tetrapods?

A

Fins to limbs
Loss of gills
Developed a mobile necj

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14
Q

What is locomotion?

A

Ability to move

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14
Q

What are tetrapods?

A

Vertebrates that live on land, characterised by 4 limbs

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15
Q

What improved from the specialisation of the vertebrae?

A

Improved locomotion & flexibility

16
Q

Respiratory changes in tetrapod?

A

Transitioned from gill-based to lung-based respiration

17
Q

What is the sacrum?

A

Forms the posterior pelvic wall & strengthens and stabilises the pelvis

18
Q

What is the sacral vertebrae?

A

Consist of 5 sacral vertebrae bones, fused together to form the sacrum

19
Q

What is the lumbar vertebrae?

A

5 cylindrical bones forming the spine of the lower back connected to the pelvis

20
Q

What is the pectoral girdle?

A

Set of bones which connectthe upper limbs to axial skeleton

21
Q

What are terrestial habitats?

A

Found on land

22
Q

What is amphibia?

A

Animals that live both on land and in water, but produce eggs in water (e.g tadpoles->frogs)

23
Q

What are aminotes?

A

Tetrapods with commitment to life on land (e.g mammals)

24
Q

How many membranes does an amniote egg have?

A

3

25
Q

What are the 3 membranes in an amniote egg?

A

Chorion, Allantois, Amnion

26
Q

What is the amnion?

A

The thin membrane that surrounds the fetus

27
Q

Function of the allantois?

A

Performs gas exchange & stores metabolic waste

28
Q

Function of chorion?

A

Outer protective membrane that surrounds the embryo

29
Q

When is the notochord in humans present?

A

During the embryonic stages of development

30
Q

What are the 2 mammalian ear bones?

A

Malleus & Incus

30
Q

What are the jaw bones ?

A

Articular & Quadrate

31
Q

What is the upper jaw joint?

A

Quadrate

32
Q

What is the lower jaw joint?

A

Articular

33
Q

Where is the location of ossicles?

A

Middle of the ear

34
Q

What is a clade?

A

A group of organisms that includes a common ancestor & all the descendants of that ancestor

35
Q

What are the 3 clades within mammalia class?

A

Boreotheria, Xenartha, Afrotheria

36
Q

What are synapomorphies?

A

Shared/derived character between ancestors & descendants

37
Q

3 key events in evolution that underpin our anatomy

A
  1. Emergence of vertebrates
  2. Emergence of gnathostomes
  3. Emergence of tetrapods