How We Do It

Coronavirus Disease 2019

HIV and AIDS: Tracking a Sexually Transmitted Virus

Robert D. Martin Ph.D. on December 1, 2020

Tree-building methods developed by evolutionary biologists revealed the origins and spread of HIV. Two types arose in Africa, one from chimpanzees and one from mangabeys.

Tree-building methods developed by evolutionary biologists revealed the origins and spread of HIV. Two types arose in Africa, one from chimpanzees and one from mangabeys.

Genetics

Erectile Dysfunction: What Causes It and What Could Fix It

Robert D. Martin Ph.D. on November 10, 2020

Erectile dysfunction, a major worldwide problem, is uniformly associated with aging. Biological and psychological factors contribute, but hardened arteries are a primary cause.

Erectile dysfunction, a major worldwide problem, is uniformly associated with aging. Biological and psychological factors contribute, but hardened arteries are a primary cause.

Coronavirus Disease 2019

Skin Colour, Vitamin D Deficits and Disease Risks

Robert D. Martin Ph.D. on October 15, 2020

Variation in human skin colour with latitude is related to ultraviolet radiation needed to produce vitamin D. Deficiency can cause health issues in many people living at high latitude.

Variation in human skin colour with latitude is related to ultraviolet radiation needed to produce vitamin D. Deficiency can cause health issues in many people living at high latitude.

Health

Vitamin D Is Essential for Human Reproduction

Robert D. Martin Ph.D. on September 15, 2020

Many people, especially those living at high latitudes, suffer from vitamin D deficiency. This has insidious effects not only on bone health but also on reproduction.

Many people, especially those living at high latitudes, suffer from vitamin D deficiency. This has insidious effects not only on bone health but also on reproduction.

Postpartum Depression

Darkness After Birth: Understanding Postpartum Depression

Robert D. Martin Ph.D. on August 20, 2020

Hard on the heels of birth, one woman in seven experiences nightmarish postpartum depression. Effective treatments exist, but seeking medical help without delay is crucial.

Hard on the heels of birth, one woman in seven experiences nightmarish postpartum depression. Effective treatments exist, but seeking medical help without delay is crucial.

Pregnancy

Coronavirus and Pregnancy: What Are the Risks?

Robert D. Martin Ph.D. on July 28, 2020

Coronavirus has been linked to increased prematurity, low birth weight, and C-section but has little effect on maternal or infant mortality. Transfer to the fetus is rare or absent

Coronavirus has been linked to increased prematurity, low birth weight, and C-section but has little effect on maternal or infant mortality. Transfer to the fetus is rare or absent

Genetics

Lactose Intolerance: When Milk Makes You Sick

Robert D. Martin Ph.D. on June 28, 2020

All suckled offspring digest lactose, the main milk sugar in placental mammals. Cheese making paved the way for human milk consumption after weaning; genetic mutation followed.

All suckled offspring digest lactose, the main milk sugar in placental mammals. Cheese making paved the way for human milk consumption after weaning; genetic mutation followed.

Menopause

Menopause Revisited: Why Don’t Men Die at 50?

Robert D. Martin Ph.D. on June 14, 2020

Human menopause is an adaptation honed by selection, not a byproduct of long lives. New facts reveal flaws in the popular "grandmother hypothesis," notably neglected grandfathers.

Human menopause is an adaptation honed by selection, not a byproduct of long lives. New facts reveal flaws in the popular "grandmother hypothesis," notably neglected grandfathers.

Menopause

Massive Mammals With Menopause

Robert D. Martin Ph.D. on May 31, 2020

Menopause is not unique to humans. It is now known to be present in at least four whale species and in Asian elephants.

Menopause is not unique to humans. It is now known to be present in at least four whale species and in Asian elephants.

Pregnancy

When a Fetus Turns to Stone

Robert D. Martin Ph.D. on March 5, 2020

Pregnancy in the abdomen outside the womb is life-threatening, but not always fatal without surgery. In very rare cases, a dead fetus becomes calcified.

Pregnancy in the abdomen outside the womb is life-threatening, but not always fatal without surgery. In very rare cases, a dead fetus becomes calcified.

Relationships

Romantic Love's Biological Foundations

Robert D. Martin Ph.D. on February 12, 2020

Romantic love is a cross-cultural human universal. Specific features of brain activation, chemical messengers, and levels of nerve growth factor accompany early-stage infatuation.

Romantic love is a cross-cultural human universal. Specific features of brain activation, chemical messengers, and levels of nerve growth factor accompany early-stage infatuation.

Mating

Just How Important Is Breast Size in Attraction?

Robert D. Martin Ph.D. on January 14, 2020

Across cultures, men do not consistently prefer large breasts.

Across cultures, men do not consistently prefer large breasts.

Pregnancy

Bountiful Breasts: Mixed Signals in Sex and Motherhood

Robert D. Martin Ph.D. on December 22, 2019

Uniquely among mammals, women’s breasts start to swell at puberty. But the evolution of breast size and men’s responses remain enigmatic.

Uniquely among mammals, women’s breasts start to swell at puberty. But the evolution of breast size and men’s responses remain enigmatic.

Artificial Intelligence

Trading Semen: The Tale of Artificial Insemination

Robert D. Martin Ph.D. on November 21, 2019

Artificial insemination, the simplest way to assist reproduction, is still widely used and even abused. Refinements include freezing semen and injection of semen into the womb.

Artificial insemination, the simplest way to assist reproduction, is still widely used and even abused. Refinements include freezing semen and injection of semen into the womb.

Health

Antibiotic Apocalypse: Going, Going, Gonorrhoea

Robert D. Martin Ph.D. on October 29, 2019

Antibiotic resistance dramatically illustrates evolutionary change under selection. Gonorrhoea and other bacteria have become superbugs, resistant to several antibiotics.

Antibiotic resistance dramatically illustrates evolutionary change under selection. Gonorrhoea and other bacteria have become superbugs, resistant to several antibiotics.

Sex

Intersex: Life in the Overlap Zone

Robert D. Martin Ph.D. on September 24, 2019

Male/female distinctions overlap in an intersex zone. Some intersex people have atypical sets of sex chromosomes, but most have gene variants on other chromosomes.

Male/female distinctions overlap in an intersex zone. Some intersex people have atypical sets of sex chromosomes, but most have gene variants on other chromosomes.

Sex

No Substitute for Sex

Robert D. Martin Ph.D. on August 20, 2019

Increasing use of “gender” as an alternative to “sex,” notably in the humanities, is inappropriate. In essence, sex is biological while gender is cultural.

Increasing use of “gender” as an alternative to “sex,” notably in the humanities, is inappropriate. In essence, sex is biological while gender is cultural.

Identity

Strange Head Shapes: Revisiting Nefertiti, Akhenaten and Tut

Robert D. Martin Ph.D. on July 30, 2019

Strange head shapes due to early binding arose sporadically worldwide. New reports add sites in northeast China, document local change and bolster findings for Ancient Egypt.

Strange head shapes due to early binding arose sporadically worldwide. New reports add sites in northeast China, document local change and bolster findings for Ancient Egypt.

Hormones

The Pope Who Advocated Birth Control

Robert D. Martin Ph.D. on June 27, 2019

Chasteberry trees contain a hormone-like substance that affects reproduction in baboons and humans. Pope John XXI prescribed a conception-blocking European type for birth control.

Chasteberry trees contain a hormone-like substance that affects reproduction in baboons and humans. Pope John XXI prescribed a conception-blocking European type for birth control.

Orgasm

Orgasms, Oxytocin, Oviducts

Robert D. Martin Ph.D. on May 31, 2019

Female orgasm is not just a functionless by-product of penis development. They are closely linked to the clitoris—part of a largely hidden complex—and may boost sperm transport.

Female orgasm is not just a functionless by-product of penis development. They are closely linked to the clitoris—part of a largely hidden complex—and may boost sperm transport.