Science and Natural History discussion

Yoohoo all who have read, speedread, seen the cover of this book, pretty much whatever you've done with it.
Any thoughts on the book?

So far it is an easy and interesting read. :)

Yes, he wrote elegantly, we can hear the wave and the sea surf when it reaches the shore.

Is this a spoiler thread or do I have to hide any spoilers? Just that it makes a discussion a bit difficult if you have to hide half the post?

My preference is to not hide spoilers--especially in nonfiction. (But even in fiction I read the end first, so that may just be me.)

This isn't really a discussion topic but I did find these interesting:

The Leatherback turtle is the only turtle without a rigid shell, but has a jigsaw mosaic of thousands of small, thin bones overlaid by a thick matrix of oily fat and fibrous tissue.

The Leatherback turtle only "warmblooded" reptile.
I double checked that one just to make sure the author wasn't sucking thumb.
Here is a link that explains how the turtle manages to be endothermic.
http://bytesizebio.net/2010/11/20/war...

The author makes an observation that (view spoiler)[there more nests in front of dark condos that produce shadows than in the nature reserve parks with low dunes and glow of the city behind them. (hide spoiler)] So, I suppose not everything man-made is "evil" and a disaster in terms of wildlife. Wildlife thriving in urban environments was something covered in another book I read recently:



What does everyone else think?

I have no further knowledge on leatherback turtle,maybe the others can shed some light on this? I read the page Elentarri posted above, so what is the current consensus? Is it endothermic or ectothermic?

Feral Cities is a new book, it will be interesting to find out whats inside.

And please dont hide anything from us, Elentarri :). I myself have only finished reading half the book.

Andreas wrote: "And please don't hide anything from us, Elentarri :). Sorry. But I'm sure you have gotten to the part I mentioned. It's right in the beginning.

Andreas wrote: "I myself have only finished reading half the book. Slow coach. ;) I will wait for the rest of you to catch up. Having a discussion with one self is rather boring. ;)

Ok :)

"there more nests in front of dark condos that produce shadows than in the nature reserve parks with low dunes and glow of the city behind them." For this one, one can argue that we shouldnt overlook what these condos and other man-made structures do to other organisms -- all the waste, the vast area of woods and mangrove claimed by men, etc certainly can be more harmful than beneficial for animals.

Andreas wrote: "And please dont hide anything from us, Elentarri :). I myself have only finished reading half the book."

I'm a little over halfway through this book too and enjoying it. Without this group I would never have picked up book on turtles. I haven't yet begun to think of leatherbacks as particularly beautiful, but then I've never actually seen one, but I'm gradually coming around to the author's point of view because he writes so eloquently about them and his experience in watching them. It's distressing mind you to realize how many are needless killed. It's enough to put one off of eating fish altogether.
I hope we can pick a book for November fairly soon - because often I don't read if I can't get the book from the library on time.
My thanks to whoever suggested this book and all of those who voted to read it. Reading it has been an eye-opener for me on several levels.

I, too, have never seen turtles from these points of view. He connected this creature to some histories. Its surprising to see some facts.

Th day after tomorrow we will start voting for november's book.
Any recommendation, Bette? You can post it here:
https://www.goodreads.com/topic/show/...

Andreas: You may be sorry you asked. : )

In Pursuit of the Unknown: 17 Equations that Changed the World by Ian Stewart
Ignorance: How it Drives Science by Stuart Fierstein
Future Science: Essays from the Cutting Edge by Max Brockton
The Man of Numbers: Fibonacci’s Arithmetic Revolution by Keith Devlin
The Brain: The Story of You by David Eagleman
Unnatural Selection: Choosing Boys over Girls, and the Consequences of a World Full of Men by Mara Hvistendahl

LOl :D. These are amazing, and truthfully, I'm a little bit aroused.

So... what does everyone think about the turtle book so far? :)

Very, very, very interesting. But any ideas on how we or mammals in general can benefit from what the leatherbacks can do?

Do we always need to benefit from something before we could be bothered to conserve it or it's habitat?

The leatherback is physiologically designed to fit into the habitat and "lifestyle" it has chosen for itself. I'm not sure any of its abilities would be of any use to someone who doesn't spend their whole life swimming in the ocean and deep diving.

Leatherbacks don't produce any medicinally useful compounds, which is probably a good thing otherwise they would be caught for that purpose as well as all the other reasons. If you want a critter that is medicinally useful you should have a look at the horseshoe crab. I found this book interesting:
Horseshoe Crab: Biography of a Survivor

I mean, wait, I'll re-read something.

Andreas wrote: "I mean, wait, I'll re-read something."
????

I might need your help:

Could you enlighten me why leatherback turtles can be the most widely distributed and the most highly migratory reptile in the world?

A few more explanations about the leatherback's ability to let its deoxygenated blood bypass its lungs and return to the muscle?

How can it have a high metabolic rate, which is NOT likely found in reptiles? All turtles have this?

Is the statement that the number of pacific leatherbacks is declining as much as 95% while its atlantic siblings are increasing in number accurate? How can this be possible?

One more thing, I couldnt find any statement regarding the symbiotic relations between the leatherbacks and other species? There isnt any? We can say that its survival is mainly due to "its being isolated from the world, its being unagressive/unresponsive toward its environment?

Do they swim in packs or couples or alone?

After all, we should learn something from them.

why leatherback turtles can be the most widely distributed and the most highly migratory reptile in the world?

Not sure why this is confusing? These turtles have a high tolerance for different climates and can therefore migrate/swim wherever they like or wherever the food is. They have all the oceans of the world to play around in. Thus, wide distribution as well.


Deoxygenated blood bypassing lungs

Leatherback blood holds large amounts of oxygen because it has more red blood cells than any other reptile. The heart is particularly large with an unusual shutting arrangement which allowed partially oxygenated (i.e. deoxygenated) blood to bypass the lungs, which need to stay compressed in long dives, to deliver more oxygen to the muscles. When they dive a sphincter closes off the blood flow to the lungs, conserving energy. I.e. the little bit of oxygen still left in the blood goes straight to the muscles where it is needed instead of going to the lungs which at that point in time don't have any oxygen due to being underwater. This saves energy. I assume completely deoxygenated blood goes to the lungs for an oxygen recharge.

Maybe this article has more info for you?
http://www.ncbi.nlm.nih.gov/pubmed/10...

high metabolic rate

Leatherback turtles are the only reptiles that qualify as warm blooded. They are usually found in warm water but they can range into cold waters in high latitudes because of their ability to generate body heat. This is achieved with a high metabolic rate, two kinds of fat and sophisticated heat-exchange system. Cold blood returning from the flippers is warmed by outgoing blood before reaching the body core. In very cold water blood flow to and from the flipper surface may shut down intermittently. The high metabolic rate is something that seems to be unique to the leatherback and related to its endothermic physiology.

pacific vs atlantic numbers

Apparently conservation efforts work better in countries bordering the atlantic than the pacific? It does seem a bit strange especially when you consider that the turtles swim everywhere. I don't remember if they were comparing turtle numbers in total or just nesting turtles.

Maybe someone else can shed light on the matter? i have a memory like a sieve and I've already sent the book back to the library.

- Heart rate vs high metabolic rate
What is high in here? Certainly not the conversion of fat into energy, through what mechanism does the turtle achieve this? Without causing an increase in oxygen consumption, this isn't easy to fathom.
From pubmed:
Heart rate declined immediately upon submergence and continued to fall during descent. All turtles showed an increase in heart rate before surfacing. The mean heart rate during dives of 17.4+/-0.9 beats min-1 (mean +/- s.d.) was significantly lower than the mean heart rate at the surface of 24.9+/-1.3 beats min-1 (P<0.05). Instantaneous heart rates as low as 1.05 beats min-1 were recorded during a 34 min dive.
We shouldnt assume that the metabolic rate is slower during dives and higher during surfacing, should we? Even if we can assume this (its easier to swim when we are not at the surface), the mean metabolic rate is still high? I read some years ago that fasting prolongs humans' lives because lower metabolic rate is associated with less cell damage, and also, less glucose in blood means less molecule (DNA, protein) glycation which can lead to damage, and also, there's a theory that cell starvation will result in the cell's defending itself against ROS and cell damage. And of course, only one study, which is VERY new (Aug 2015), that says that individuals with higher oxygen consumption rates can actually have lower levels of H2O2." (http://m.rsbl.royalsocietypublishing....)
I should perhaps add that I'm a medical doctor so I'm familiar with these concepts.

Thank you so much,the lung sphincter thing is interesting. Any thoughts on my second post, regardin the symbiotic relations and others?