Lesson 7 Flashcards
In the mid- ____s, scientists started to give every species its own unique name
1700s
this led to some confusion: people were using different names for the same species
Approx how many species are on earth?
between 5 and 30 million (we don’t really know and probably never will)
_____ _____ wrote a big book listing every known organism, and introduced a simple binomial naming system for every organism
Carl Linneaus
Explain the parts of the binomial naming system
eg. Homo sapiens
Genus= homo: generic name (always capitalized)
Species (specific epithet)= sapiens (always lowercase)
the whole thing written in italics
t/f
2 very closely related species can be named the same thing
FALSE
every species, no matter how similar, has their own name
Rule of Priority=
once a species has been named and widely distributed/ accessible in literature, it cannot be renamed.
What are 2 exceptions of the rule of priority?
- If a new organism was accidentally given the same name as an already existing organism (happens sometimes)
- if the organism wasn’t really a new species at all (lump it back in with the old species)
Holotype=
the single specimen that you state as THE specimen, that in itself is a definition of the species
T/F
For something extinct like dinosaurs, the holotype can be a single fossil
true
just needs to be accessible for other scientists to come look at it
T/F
You can name up to 3 holotypes for each species
false
There is only ever 1 holotype. You can designate alternative specimens, but they’re given alternate names like “paratype” or “lectotype”
How many species of non-avian dinosaurs have been named so far?
Around 1000 (always changing)
Hesperonychus was a small carnivorous dinosaur, probably about the size of a _____
- was named at ____ _ ___
- found in _______ _______ ______
chicken
university of alberta
dinosaur provincial park
t/f many species are named from partial skeletons
true
rarely find a whole skeleton in the field
What is the holotype for Hesperonychus?
The pelvis fossil, stored at U of A
How can you tell is a dinosaur was an adult by their pelvis?
If the ilium and pubis are fused together, it was an adult. This inly happens when an animal is mature
Which is the most reliable feature that scientists can use to divide up organisms into separate species?
a. presence/ absence of antlers
b. # of fingers on the hand
c. color of skin/ feathers
d. length of limbs
b. # of fingers on the hand
This is the most unchanging characteristic
Intraspecific variation=
differences within a species
It’s important to account for this when trying to determine if an organism is a new species or not
3 kinds of intraspecific variation:
1. Individual variation=
the normal variation you see among individuals of any species (eg exact shape of antlers)
3 kinds of intraspecific variation:
- Ontogenetic variation=
variation because of age and growth (eg size of antlers: bigger= older)
3 kinds of intraspecific variation:
- sexual variation=
variation between males and females (eg presence/ absence of antlers)
Morphological Species Concept=
All organisms which look the same are considered a single species
- there can be some variation b/w individuals, but if they look more or less the same, then they’re considered to be one species
useful concept but not foolproof!
t/f
sometimes we need a certain body part to tell 2 species apart
true
sometimes the bodies of 2 species are almost identical, but the skulls, for example, are entirely different
What’s one of the biggest issues with the morphological species concept?
sometimes members of the same species are split into different species because they look different
eg. dogs! All the different breeds look very different, but they’re all one species and can breed with each other
Biological Species Concept=
defines a species as the group of organisms which can interbreed
addresses cryptic species issue of morphological species concept
this is the concept we use for dogs
Very hard to apply this concept sometimes, especially for extinct species
For any 2 individuals to reproduce, the organisms need to live in the same ___ at the same ___, but do not have to look the same
place
time
population=
a group of animals in the same geographic area that can potentially mate
which is true?
a. One or more species make up a population
b. One or more populations make up a species
b. One or more populations make up a species
some live in different places, but are still the same species
t/f
sometimes it comes down the the judgement of a scientist as to whether or not something is a new species
true
especially if we’re only dealing with fragment remains
taxonomy=
the naming of species
