From: mk_thisisit
Research into early human development is driven by a fundamental fascination with the beginning of life and existence, especially the journey that occurs silently within the mother’s body [00:00:15]. This stage, full of transformations, is considered the deepest mystery of human existence [00:00:39]. Understanding it is crucial for preventing losses in the future and supporting life from its earliest moments [00:01:00].
Pioneering Research and the “Black Box”
Professor Magdalena Żernicka-Goetz, a leading Polish scientist and the first Polish woman to hold a professorship at the University of Cambridge [00:01:08], has been at the forefront of this field. Her laboratory was the first to conduct research on human embryos up to day 14 of their development [00:00:00], opening a new chapter in human development research [00:00:09]. This breakthrough was named the scientific breakthrough of 2016 by Science magazine [00:01:30].
For a long time, the period of human development between 5 and 14 days was known as the “black box” because it was completely inaccessible to scientists [00:03:10]. Previously, embryos could only be examined for the first five days, after which implantation in the uterus was required [00:03:20]. Żernicka-Goetz’s laboratory developed a method allowing embryos to develop an additional seven days, extending observation into this critical period when the highest number of miscarriages naturally occur [00:03:36]. This achievement enabled understanding of crucial factors and cell interactions for proper development and pregnancy [00:03:51].
Human Embryo Models and Stem Cells
Beyond direct embryo research, her team later created the first human embryo models based on stem cells [00:04:22]. These models are living, embryo-like structures created from stem cells that mimic early human development [00:04:59]. They are not exact copies of human embryos and cannot develop into a complete human organism [00:09:45] [00:05:07]. Their purpose is to study how cells interact, communicate, and self-organize, revealing fundamental mechanisms of life’s origin [00:05:18] [00:08:03] [00:10:48].
Stem cells, first isolated in 1981, have unlimited development potential, transforming into different cell types and creating complex organ-like structures (organoids) [00:08:34] [00:06:57]. Żernicka-Goetz’s lab succeeded in combining embryonic stem cells with two types of extraembryonic cells (which form structures like the placenta) to create these models [00:07:47] [00:09:07]. This discovery was published in Science in 2017 [00:09:19]. The creation of human embryo models from stem cells was recognized as the “method of the year” in 2023 [00:12:47].
The use of artificial intelligence assists this research by analyzing thousands of embryo development recordings to predict which embryos will develop successfully [00:32:00].
The Fragility of Early Pregnancy and Personal Motivation
A significant driving force behind this research is the high rate of early pregnancy failures. Approximately 60% of all pregnancies end within the first two weeks of life, often before a woman even realizes she is pregnant [00:18:27]. This highlights the extreme fragility of the beginning of human existence [00:18:42].
Professor Żernicka-Goetz’s personal experience with her own pregnancy significantly shifted her research focus [00:22:06]. During her second pregnancy, a prenatal test revealed abnormal cells in her son’s embryo, with as many as 25% of cells showing an abnormal set of chromosomes [00:19:43]. It later turned out these abnormalities were confined to the placenta [00:21:26]. This experience made her realize the importance of understanding why so many human pregnancies fail [00:20:07].
Embryo Self-Correction and Asymmetry
Her research using mouse embryos revealed that if chromosomal changes occur in the embryo, these abnormal cells can be eliminated at a very early stage, especially from the part that forms the baby’s body [00:22:36]. Cells with abnormalities may, however, be tolerated in the placenta [00:22:57]. This demonstrates the “extraordinary strength and plasticity” of embryos to save themselves when things go wrong [00:23:01]. This mechanism is, in a sense, the opposite of cancer, where abnormal cells take over [00:36:46]. Understanding this could lead to treatments for infertility [00:36:59].
Further surprising discoveries include the finding that most of the human body originates from just one of the two cells at the initial two-cell stage after fertilization [00:49:07]. The other cell primarily contributes to the placenta. The reasons for this early asymmetry are not yet understood but highlight a “subtle unevenness” at the very start of life [00:49:40].
Ethical Considerations and the 14-Day Rule
The 14-day rule is an established ethical and experimental boundary in human embryo research [00:11:09] [00:14:31]. This rule was established many years ago, and while it may seem arbitrary, it has historical and ethical premises [00:12:29]. It marks the time when the embryo begins gastrulation, a “magical moment” where the body’s axis forms and cells arrange into future body structures [00:14:35]. At 14 days, the embryo is still microscopic, like a bean [00:14:59]. Importantly, models created from stem cells cannot develop into a full human organism and are designed solely for laboratory testing [00:09:45] [00:10:22]. Conducting experiments inconsistent with ethical standards, such as implanting a model, is strictly prohibited [00:10:15].
Despite groundbreaking scientific achievements, human embryo research and development often faces public misunderstanding and controversy [00:41:04]. Researchers emphasize that their goal is to protect life and understand fundamental biological mechanisms, not to create humans in test tubes [00:41:32] [00:45:54]. Ethical limits, such as the 14-day rule, are strictly respected to ensure research integrity and public trust [00:46:08]. Manipulation for purposes inconsistent with knowledge and ethics, like creating hybrid organisms for development outside the lab, is strictly prohibited [00:46:33].
Defining Life and Future Impact
The question of “what is life” is profound. For Żernicka-Goetz, embryos represent life dynamic, evolving, and on its unique journey [00:25:26]. When asked what makes us human, she suggests that what is called the “soul” might emerge when the nervous system begins to form and the ability to feel, react, and communicate appears [00:26:07]. The embryos studied are at an earlier stage, without a nervous system, preparing the ground for its later formation [00:26:20]. This perspective informs her book, “The Dance of Life: How Do We Become Human?” [00:26:57].
The ultimate goal of this research is to answer fundamental questions about our existence and contribute to protecting pregnancies that currently fail for unknown reasons [00:23:21]. The ability to study the critical early stage of human development has opened entirely new possibilities for understanding the beginning of life [00:24:50].