Audio Transcript Auto-generated
- 00:01 - 00:03
Hello. My name is Jacqueline Homes, and I'm going to
- 00:03 - 00:06
be talking about the structure and functions of dolphins and
- 00:06 - 00:08
sharks and their similarities and differences.
- 00:11 - 00:13
For starters, we're going to be talking about the analogous
- 00:13 - 00:16
structure of the skeleton of each of these animals.
- 00:16 - 00:19
Analogous means that they do not come from a common
- 00:19 - 00:24
ancestor due to these structural differences, which make them unique
- 00:24 - 00:24
to themselves.
- 00:26 - 00:28
So for starters, we're going to talk about the bones.
- 00:29 - 00:32
However, inside a shark they do not have bones.
- 00:32 - 00:34
They have cartilage, which is more flexible.
- 00:34 - 00:36
And it's lighter than a bone, which makes it easier
- 00:37 - 00:40
for them to swim in the oceans and to gain
- 00:40 - 00:42
more speed without the bones weighing them down.
- 00:44 - 00:46
So as we have said that, the dolphins do have
- 00:46 - 00:49
bones, and with that, there has been research that there
- 00:49 - 00:53
were little almost hind looking legs in the back of
- 00:53 - 00:57
their body, which made it seem like they could have
- 00:57 - 01:00
been amphibious and come from a common ancestor of an
- 01:00 - 01:03
amphibian rather than you know, a fish or a mammal.
- 01:04 - 01:07
So that's something that's different compared to the shark that
- 01:07 - 01:10
is a fish with cartilage, not bones.
- 01:12 - 01:15
Yeah, so next, we are going to talk about the
- 01:15 - 01:16
homologous structure.
- 01:17 - 01:21
The homologous structure is structures that are similar, similar in
- 01:21 - 01:25
function and could relate back to a common ancestor, unlike
- 01:25 - 01:26
the analogous structures.
- 01:28 - 01:31
So for the homologous, there is a dorsal fin.
- 01:31 - 01:34
Although the fins are different, they are still a dorsal
- 01:34 - 01:36
fin on the top of their body, where it is
- 01:36 - 01:39
exposed outside of the ocean.
- 01:39 - 01:42
When you can see the little thin over the ocean
- 01:43 - 01:47
water, they also live in oceans and swim, which is
- 01:47 - 01:48
nothing really new.
- 01:49 - 01:51
They also have teeth in both of them.
- 01:52 - 01:54
Whether they are the same looking teeth where they're flat
- 01:55 - 01:58
edged or sharp, they both have teeth, which make it
- 01:58 - 02:00
so that they're able to eat certain foods.
- 02:00 - 02:03
One common food that they can eat is actually fish
- 02:04 - 02:07
because dolphins are carnivores as well.
- 02:07 - 02:08
So they eat fish, squid.
- 02:10 - 02:14
All this stuff they also and both animals have really
- 02:14 - 02:14
good vision.
- 02:15 - 02:17
So it is said that the dolphin can see in
- 02:17 - 02:20
both the ocean water and above the water as well.
- 02:21 - 02:25
The quality above the water isn't as good as below.
- 02:25 - 02:27
The water over there is still able to see below
- 02:27 - 02:30
the water and have good vision, just like the sharks,
- 02:30 - 02:32
who have really good vision underneath the water as well.
- 02:35 - 02:38
In both of the animals, they are able to swim
- 02:38 - 02:40
at higher speeds due to their skin.
- 02:42 - 02:46
Now in the dolphin, the dolphin has blubber it.
- 02:46 - 02:50
Also, when it goes by water and the water flows
- 02:51 - 02:54
past the skin, it creates a turbulence, which makes them
- 02:54 - 02:58
swim a little faster compared to two no water flowing
- 02:59 - 03:00
in them slowing down.
- 03:01 - 03:04
The shark also has a unique skin where it's almost
- 03:04 - 03:07
like the scales are almost teeth like.
- 03:07 - 03:10
They have said inside the articles that I've read, which
- 03:11 - 03:14
it reduces friction from the water into their skin, and
- 03:14 - 03:16
it increases their speed as well, which is very interesting
- 03:17 - 03:19
because I've never known anything like that.
- 03:22 - 03:25
So next major difference, although we have said multiple differences,
- 03:26 - 03:28
is that one is a fish and one is a
- 03:29 - 03:31
mammal. The shark, as I said before, is a fish,
- 03:32 - 03:33
and the dolphin is a mammal.
- 03:34 - 03:37
The dolphin actually has little hairs on its body, which
- 03:37 - 03:39
make it so that it's classified as a mammal, plus
- 03:40 - 03:43
more more research with in the articles that sit with
- 03:43 - 03:46
the hind legs, which can actually make a lot more
- 03:46 - 03:50
sense that they would be considered a mammal considering of
- 03:50 - 03:56
the common ancestor of mammals having legs also within the
- 03:57 - 04:00
animals. The dolphin has a blowhole, so it is able
- 04:01 - 04:04
to breathe in air and blow out water compared to
- 04:04 - 04:06
the shark that has gills that make it breathe in
- 04:07 - 04:08
the water.
- 04:08 - 04:10
And that is how they actually survive.
- 04:12 - 04:16
And it makes it so that, you know, they're able
- 04:16 - 04:19
to breathe underwater, classified as a fish for breathing underwater
- 04:20 - 04:23
and then the mammal for breathing in air and having
- 04:23 - 04:23
the blowhole.
- 04:26 - 04:27
So that is all for today.
- 04:28 - 04:30
Here is just the sources that I used for my
- 04:31 - 04:34
images. And then after the image sources, there is going
- 04:34 - 04:36
to be the sources that I used originally.
- 04:36 - 04:38
This is just one of the sources that are used,
- 04:38 - 04:40
and the other two are located right there.
- 04:41 - 04:42
Thank you for listening.