Andrew Cooke | Contents | Latest | RSS | Previous | Next

C[omp]ute

Welcome to my blog, which was once a mailing list of the same name and is still generated by mail. Please reply via the "comment" links.

Always interested in offers/projects/new ideas. Eclectic experience in fields like: numerical computing; Python web; Java enterprise; functional languages; GPGPU; SQL databases; etc. Based in Santiago, Chile; telecommute worldwide. CV; email.

Personal Projects

Choochoo Training Diary

Last 100 entries

Surprise Paradox; [Books] Good Author List; [Computing] Efficient queries with grouping in Postgres; [Computing] Automatic Wake (Linux); [Computing] AWS CDK Aspects in Go; [Bike] Adidas Gravel Shoes; [Computing, Horror] Biological Chips; [Books] Weird Lit Recs; [Covid] Extended SIR Models; [Art] York-based Printmaker; [Physics] Quantum Transitions are not Instantaneous; [Computing] AI and Drum Machines; [Computing] Probabilities, Stopping Times, Martingales; bpftrace Intro Article; [Computing] Starlab Systems - Linux Laptops; [Computing] Extended Berkeley Packet Filter; [Green] Mainspring Linear Generator; Better Approach; Rummikub Solver; Chilean Poetry; Felicitations - Empowerment Grant; [Bike] Fixing Spyre Brakes (That Need Constant Adjustment); [Computing, Music] Raspberry Pi Media (Audio) Streamer; [Computing] Amazing Hack To Embed DSL In Python; [Bike] Ruta Del Condor (El Alfalfal); [Bike] Estimating Power On Climbs; [Computing] Applying Azure B2C Authentication To Function Apps; [Bike] Gearing On The Back Of An Envelope; [Computing] Okular and Postscript in OpenSuse; There's a fix!; [Computing] Fail2Ban on OpenSuse Leap 15.3 (NFTables); [Cycling, Computing] Power Calculation and Brakes; [Hardware, Computing] Amazing Pockit Computer; Bullying; How I Am - 3 Years Post Accident, 8+ Years With MS; [USA Politics] In America's Uncivil War Republicans Are The Aggressors; [Programming] Selenium and Python; Better Walking Data; [Bike] How Fast Before Walking More Efficient Than Cycling?; [COVID] Coronavirus And Cycling; [Programming] Docker on OpenSuse; Cadence v Speed; [Bike] Gearing For Real Cyclists; [Programming] React plotting - visx; [Programming] React Leaflet; AliExpress Independent Sellers; Applebaum - Twilight of Democracy; [Politics] Back + US Elections; [Programming,Exercise] Simple Timer Script; [News] 2019: The year revolt went global; [Politics] The world's most-surveilled cities; [Bike] Hope Freehub; [Restaurant] Mama Chau's (Chinese, Providencia); [Politics] Brexit Podcast; [Diary] Pneumonia; [Politics] Britain's Reichstag Fire moment; install cairo; [Programming] GCC Sanitizer Flags; [GPU, Programming] Per-Thread Program Counters; My Bike Accident - Looking Back One Year; [Python] Geographic heights are incredibly easy!; [Cooking] Cookie Recipe; Efficient, Simple, Directed Maximisation of Noisy Function; And for argparse; Bash Completion in Python; [Computing] Configuring Github Jekyll Locally; [Maths, Link] The Napkin Project; You can Masquerade in Firewalld; [Bike] Servicing Budget (Spring) Forks; [Crypto] CIA Internet Comms Failure; [Python] Cute Rate Limiting API; [Causality] Judea Pearl Lecture; [Security, Computing] Chinese Hardware Hack Of Supermicro Boards; SQLAlchemy Joined Table Inheritance and Delete Cascade; [Translation] The Club; [Computing] Super Potato Bruh; [Computing] Extending Jupyter; Further HRM Details; [Computing, Bike] Activities in ch2; [Books, Link] Modern Japanese Lit; What ended up there; [Link, Book] Logic Book; Update - Garmin Express / Connect; Garmin Forerunner 35 v 230; [Link, Politics, Internet] Government Trolls; [Link, Politics] Why identity politics benefits the right more than the left; SSH Forwarding; A Specification For Repeating Events; A Fight for the Soul of Science; [Science, Book, Link] Lost In Math; OpenSuse Leap 15 Network Fixes; Update; [Book] Galileo's Middle Finger; [Bike] Chinese Carbon Rims; [Bike] Servicing Shimano XT Front Hub HB-M8010; [Bike] Aliexpress Cycling Tops; [Computing] Change to ssh handling of multiple identities?; [Bike] Endura Hummvee Lite II; [Computing] Marble Based Logic; [Link, Politics] Sanity Check For Nuclear Launch; [Link, Science] Entropy and Life

© 2006-2017 Andrew Cooke (site) / post authors (content).

Evolution of Colour

From: andrew cooke <andrew@...>

Date: Sun, 11 Dec 2011 17:56:25 -0300

OK, so here's a possibly interesting question that just came up while talking
to Paulina: how did colour vision evolve?

You might answer: so that animals could see more detail.  But what would they
see?  Most natural things are either brown or green.  And the blue sky.  Is
that enough to motivate three colour vision?

"What about colourful flowers, or fruit, or birds?" you might ask.  But then
how did *they* evolve?  Because I would have thought that the standard
explanation there is that they are evolved to be attractive to colour vision.

So apart from green / brown / blue, we seem to have a chicken and egg
situation: bright plumage / fruit / flowers wouldn't evolve until there was
colour vision to detect them; but without them, why evolve colour vision?

Presumably things boot-strapped on green / brown / blue and then more
resolution / brighter colours co-evolved.  Which I guess works, but isn't as
cute a "just so" story as you might hope.

Or maybe there's some technical argument that says that green / brown / blue
requires three detectors (why not two?)...

Andrew

evolution of color vision

From: Stefan Wehner <stefan@...>

Date: Sun, 11 Dec 2011 19:31:26 -0500

I remember too, it has to do with the color of fruit and the different =
hues of green (and even red) which mark the younger and more nutritious =
leaves. A couple of years ago I read a book about evolution: Sean B. =
Carroll: The making of the fittest. It devotes a whole chapter on the =
issue and goes into the details of which molecules are responsible for =
which color, what are the genes that codify them and how these genes =
shifted between different animals. By the way, only the Old World apes =
have trichromatic color vision. American monkeys as well as rodents and =
other mammals only developed dichromatic vision. Birds and even fish can =
see colors and it seems that color vision was acquired early in =
evolution, then lost in many species and subsequently redeveloped. =
Pretty fascination topic and I can recommend the book.

Stefan=

Seeing red

From: Manuel Simoni <msimoni@...>

Date: Sun, 11 Dec 2011 22:07:47 +0100

From Wikipedia's http://en.wikipedia.org/wiki/Evolution_of_color_vision

"Ability to perceive red and orange hues allows tree-dwelling primates
to discern them from violet. This is particularly important for
primates in the detecton of red and orange fruit, as well as
nutrient-rich new foliage, in which the red and orange carotenoids
have not yet been masked by chlorophyll."

Comment on this post